Optical fiber-based distributed antenna systems, components, and related methods for calibration thereof

ABSTRACT

Optical fiber-based wireless systems and related components and methods are disclosed. The systems support radio frequency (RF) communications with clients over optical fiber, including Radio-over-Fiber (RoF) communications. The systems may be provided as part of an indoor distributed antenna system to provide wireless communication services to clients inside a building or other facility. The communications can be distributed between a head end unit (HEU) that receives carrier signals from one or more service or carrier providers and converts the signals to RoF signals for distribution over optical fibers to end points, which may be remote antenna units (RAUs). In one embodiment, calibration of communication downlinks and communication uplinks is performed to compensate for signal strength losses in the system.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/915,882, filed Jun. 12, 2013, which is a continuation of U.S.application Ser. No. 13/194,410, filed Jul. 29, 2011, which is acontinuation of International Application No. PCT/US2010/022857, filedFeb. 2, 2010, which claims the benefit of priority of U.S. ProvisionalApplication No. 61/149,553, filed Feb. 3, 2009 and entitled “DistributedAntenna System,” and to U.S. Provisional Application No. 61/230,463,filed Jul. 31, 2009 and entitled “Optical Fiber-Based DistributedAntenna Systems, Components, and Related Methods for CalibrationThereof,” the contents of which are relied upon and incorporated hereinby reference in their entireties.

This application is related to International Application No.PCT/US2010/022847, filed Feb. 2, 2010, and to U.S. ProvisionalApplication No. 61/230,472 filed Jul. 31, 2009 and entitled “OpticalFiber-Based Distributed Antenna Systems, Components, and Related Methodsfor Monitoring the Status Thereof,” which are incorporated herein byreference in their entireties.

BACKGROUND

Field of the Disclosure

The technology of the disclosure relates to optical fiber-baseddistributed antenna systems for distributing radio frequency (RF)signals over optical fiber to remote antenna units and related controlsystems and methods.

Technical Background

Wireless communication is rapidly growing, with ever-increasing demandsfor high-speed mobile data communication. As an example, so-called“wireless fidelity” or “WiFi” systems and wireless local area networks(WLANs) are being deployed in many different types of areas (e.g.,coffee shops, airports, libraries, etc.). Wireless communication systemscommunicate with wireless devices called “clients,” which must residewithin the wireless range or “cell coverage area” in order tocommunicate with an access point device.

One approach to deploying a wireless communication system involves theuse of “picocells.” Picocells are radio frequency (RF) coverage areas.Picocells can have a radius in the range from a few meters up to twentymeters as an example. Combining a number of access point devices createsan array of picocells that cover an area called a “picocellular coveragearea.” Because the picocell covers a small area, there are typicallyonly a few users (clients) per picocell. This allows for minimizing theamount of RF bandwidth shared among the wireless system users. It may bedesirable to provide picocells in a building or other facility toprovide wireless communication system access to clients within thebuilding or facility. However, it may be desirable to employ opticalfiber to distribute communication signals. Benefits of optical fiberinclude higher signal-to-noise ratios and increased bandwidth.

SUMMARY OF THE DETAILED DESCRIPTION

Embodiments disclosed in the detailed description include opticalfiber-based distributed antenna systems that provide communicationsignals over optical fiber to clients. The communication signals may bewireless communication signals. The distributed antenna systems may beprovided as part of an indoor distributed antenna system (IDAS) toprovide wireless communication services to clients inside a building orother facility, as an example. The systems may distribute communicationsignals by employing Radio-over-Fiber (RoF) communications utilizingfiber optic cable distribution.

In one embodiment, a wireless communication system comprises a downlinkbase transceiver station (BTS) interface configured to receive downlinkelectrical radio frequency (RF) signals from at least one BTS, and atleast one optical interface module (OIM). The OIM is configured toreceive and convert the downlink electrical RF signals from the downlinkBTS interface into downlink Radio-over-Fiber (Ron signals on at leastone communication downlink, and receive and convert uplink RoF signalsfrom at least one remote antenna unit (RAU) into uplink electrical RFsignals on at least one communication uplink. The system furthercomprises an uplink BTS interface configured to receive and communicatethe uplink electrical RF signals from the at least one communicationuplink to the at least one BTS, and a controller. The controller isconfigured to inject at least one calibration signal over the at leastone communication downlink, calibrate at least one downlink gain in theat least one communication downlink based on a loss incurred in the atleast one calibration signal in the at least one communication downlink,cause the at least one calibration signal to be switched from the atleast one communication downlink to the at least one communicationuplink, and calibrate at least one uplink gain in the at least onecommunication uplink based on a loss incurred in the at least onecalibration signal in the at least one communication uplink.

Additional features and advantages will be set forth in the detaileddescription which follows, and in part will be readily apparent to thoseskilled in the art from that description or recognized by practicing theinvention as described herein, including the detailed description thatfollows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description present embodiments, and are intendedto provide an overview or framework for understanding the nature andcharacter of the disclosure. The accompanying drawings are included toprovide a further understanding, and are incorporated into andconstitute a part of this specification. The drawings illustrate variousembodiments, and together with the description serve to explain theprinciples and operation of the concepts disclosed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram of an exemplary optical fiber-basedwireless system, according to one embodiment;

FIG. 2 is a schematic diagram of the optical fiber-based wireless systemof FIG. 1;

FIG. 3 is a schematic diagram of an exemplary optical fiber-basedwireless system that includes a central head-end unit;

FIG. 4 is a schematic diagram of an exemplary central head-end unit;

FIG. 5A is a close-up schematic diagram of an optical fiber cableshowing downlink and uplink optical fibers connected to remote unitsincorporated in an outer jacket of the optical fiber cable;

FIG. 5B is a schematic diagram of an exemplary optical fiber cableshowing downlink and uplink optical fibers connected to remote unitsprovided outside an outer jacket of the optical fiber cable;

FIG. 6 is a close-up view of one exemplary remote unit illustrating acorresponding exemplary picocell and the exchange of downlink and uplinkelectromagnetic signals between the remote unit and client deviceswithin the picocell;

FIG. 7 is a schematic diagram of an exemplary centralized opticalfiber-based wireless system;

FIG. 8 is a top down view of the wireless picocellular system of FIG. 7showing an extended picocellular coverage area formed by using multipleoptical fiber cables;

FIG. 9A is a schematic cut-away diagram of an exemplary buildinginfrastructure in which an optical fiber-based wireless system accordingto the embodiments described herein could be employed;

FIG. 9B is a schematic diagram of an example embodiment of amulti-section cable used in the optical fiber-based wireless system ofFIG. 9A to distribute transponders throughout the buildinginfrastructure;

FIG. 10 is a schematic top down view of the second floor of the buildinginfrastructure in FIG. 9A showing three exemplary optical fiber cablesbranching out extending over the ceiling;

FIG. 11A is a schematic diagram of an exemplary optical fiber-basedwireless system incorporating multiple head-end units or stations;

FIG. 11B is a partially schematic cut-away diagram of an exemplarybuilding infrastructure in which the optical fiber-based wireless systemof FIG. 8 can be employed;

FIG. 12A is an exemplary schematic diagram of an exemplary head-endunit;

FIG. 12B is another exemplary schematic diagram of an exemplary head-endunit;

FIG. 13 is a front exterior view of the head-end unit of FIGS. 12A and12B;

FIG. 14 is a rear exterior view of the head-end unit of FIGS. 12A and12B;

FIG. 15A is a schematic diagram of an optical interface card (OIC) whichcan be employed in the head-end unit of FIGS. 12A and 12B;

FIG. 15B is a schematic diagram of an alternative OIC which can beemployed in the head-end unit of FIGS. 12A and 12B;

FIG. 16A is an another schematic diagram of the OIC of FIG. 15A and/orFIG. 15B;

FIG. 16B is an another schematic diagram of the OIC of FIG. 15A and/orFIG. 15B;

FIG. 17 illustrates perspective and end views of an exemplary opticalinterface module (OIM);

FIG. 18A is a schematic diagram of an exemplary downlink basetransceiver station (BTS) interface card (BIC);

FIG. 18B is a schematic diagram of another exemplary downlink BIC;

FIG. 19A is a schematic diagram of an exemplary downlink BIC uplink;

FIG. 19B is a schematic diagram of another exemplary downlink BICuplink;

FIG. 20 is a schematic diagram of an exemplary remote unit whichprovides remotely located endpoints for service signal distribution forthe wireless picocellular system of FIG. 8;

FIG. 21 is a perspective view of an exemplary remote unit with the coverof the remote unit omitted to show the interior of the remote unit;

FIG. 22 is a side view of the exemplary remote unit of FIG. 21;

FIG. 23 is a schematic diagram of another exemplary optical fiber-basedwireless system that includes components employing microprocessorsexecuting software to provide certain access and functionalities;

FIG. 24 is a schematic diagram of the optical fiber-based wirelesssystem of FIG. 23 illustrating an interface layer and exemplary clientsaccessing the optical fiber-based wireless system via the interfacelayer;

FIG. 25A is a schematic diagram of an exemplary microprocessor andsoftware deployment diagram of the optical fiber-based wireless systemof FIG. 23 and external components that can interface with the opticalfiber-based wireless system;

FIG. 25B is a table illustrating visual indicators that can be providedon a module of the optical fiber-based wireless system;

FIG. 26 is a schematic diagram of the exemplary addressing betweendownlink and uplink base transceiver (BTS) interface cards (BICs),optical interface OICs, and remote antenna units (RAUs);

FIG. 27 is an exemplary communication address format for communicationsbetween the downlink and uplink BICs and the OICs and RAUs;

FIG. 28A is an exemplary point format for points communicated in theoptical fiber-based wireless system of FIG. 23;

FIG. 28B is an exemplary hardware points list for storing hardwareinformation about points provided in the optical fiber-based wirelesssystem of FIG. 23;

FIG. 28C is an exemplary points list accessible by a communicationsmodule in the HEU of the optical fiber-based wireless system of FIG. 23;

FIG. 29 is an exemplary flagbits format to provide characteristicinformation regarding its points to the head-end unit (HEU) for variouscomponents in the optical fiber-based wireless system of FIG. 23;

FIG. 30 is an exemplary thread diagram in an HEU controller of the HEUof the optical fiber-based wireless system of FIG. 23;

FIG. 31 is a flowchart illustrating an exemplary process performed bythe HEU controller in the optical fiber-based wireless system;

FIG. 32 is an exemplary HEU controller thread startup sequencecommunication diagram for the HEU controller;

FIGS. 33A and 33B are a flowchart illustrating an exemplary processperformed by a scheduler thread in the HEU controller;

FIG. 34 is an exemplary module state diagram for modules in the opticalfiber-based wireless system of FIG. 23;

FIG. 35 is an exemplary communications thread communication diagram toreceive and process communication requests;

FIG. 36 illustrates an exemplary sequence diagram illustrating callsmade to process alarm points involving scheduler and logger threads;

FIG. 37 illustrates an exemplary event logging sequences to log systemevents for the optical fiber-based wireless system optical fiber-basedwireless system;

FIGS. 38A-38C illustrate an exemplary schematic diagram of the opticalfiber-based wireless system of FIG. 23 illustrating the components ofthe HEU, the uplink and downlink BICs, the OIMs, and the RAUs and thedownlink and the uplink communication paths therein;

FIGS. 39A and 39B illustrate a flowchart illustrating an exemplarycalibration thread to calibrate components of the optical fiber-basedwireless system;

FIG. 40 is a schematic diagram of an exemplary master and slave HEUconfiguration;

FIGS. 41A-41C are schematic diagram of other exemplary multiple HEUconfigurations;

FIG. 42 is an exemplary web browser login page for web client access theHEU;

FIG. 43 is a default page supported by the HEU and displayed on a webbrowser client;

FIGS. 44-45 are exemplary default pages illustrating a default statusessupported by the HEU and displayed on a web browser client;

FIG. 46 is an exemplary HEU configuration page supported by the HEU anddisplayed on a web browser client;

FIG. 47A is an exemplary link configuration page supported by the HEUand displayed on a web browser client;

FIG. 47B is an exemplary add user page supported by the HEU anddisplayed on a web browser client;

FIG. 47C is an exemplary points information page supported by the HEUand displayed on a web browser client;

FIG. 48 is an exemplary system monitor page supported by the HEU anddisplayed on a web browser client;

FIG. 49 is an exemplary system alarm page supported by the HEU anddisplayed on a web browser client;

FIGS. 50A and 50B illustrate an exemplary log page supported by the HEUand displayed on a web browser client;

FIG. 51A is an exemplary properties page supported by the HEU anddisplayed on a web browser client;

FIG. 51B is an exemplary installation page supported by the HEU anddisplayed on a web browser client;

FIG. 52 is an exemplary user configuration supported by the HEU anddisplayed on a web browser client;

FIG. 53 is an exemplary network setup configuration supported by the HEUand displayed on a web browser client;

FIG. 54 is an exemplary system HEUs page supported by the HEU anddisplayed on a web browser client;

FIG. 55 is an exemplary service notes page supported by the HEU anddisplayed on a web browser client; and

FIG. 56 is an exemplary system information page supported by the HEU anddisplayed on a web browser client.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings, in which some,but not all embodiments are shown. Indeed, the concepts may be embodiedin many different forms and should not be construed as limiting herein;rather, these embodiments are provided so that this disclosure willsatisfy applicable legal requirements. Whenever possible, like referencenumbers will be used to refer to like components or parts.

Embodiments disclosed in the detailed description include opticalfiber-based distributed antenna systems that provide communicationsignals over optical fiber to clients. The communication signals may bewireless communication signals. The distributed antenna systems may beprovided as part of an indoor distributed antenna system (IDAS) toprovide wireless communication services to clients inside a building orother facility, as an example. The systems may distribute communicationsignals by employing Radio-over-Fiber (RoF) communications utilizingfiber optic cable distribution.

In one embodiment, the optical fiber-based wireless systems can employ ahead-end unit (HEU) or controller that receives radio frequency (RF)carrier signals from one or more service or carrier providers. The HEUis a host neutral device that supports and distributes carrier signalcommunications over optical fibers to end points, which may be remoteantenna units (RAUs). The RF carrier signals are converted to RoFsignals and provided to the RAUs, wherein the RoF signals are convertedback to electrical RF signals and wirelessly communicated to clientdevices in the coverage area of the RAUs. The RAUs can be installed inlocations throughout a building or facility to form a seamless coveragearea. The HEU can be configured to interface with a desired number ofRAUs to define coverage areas.

In one embodiment, the HEU contains a downlink base transceiver station(BTS) interface and an uplink BTS interface to support interfacing withdownlink and uplink communication links for one or more BTSs. Thedownlink BTS interface is configured to receive electrical RF signalsfrom multiple BTSs and provide the electrical RF signals to opticalinterface modules (OIMs). The OIMs contain electrical-to-optical (E/O)converters that convert the electrical RF signals received on thedownlink into RoF signals (for transmission over optical fiber to RAUssupported by the OIMs. The RoF signals received by the RAUs on thedownlink are converted into electrical RF signals using anoptical-to-electrical (O/E) converter and radiated through antennas toclient devices in range of the antennas to establish downlinkcommunications between client devices and the BTSs. For uplinkcommunications, the RAUs are also configured to receive electrical RFsignals at the antennas from clients, which are converted to RoF signalsand communicated back to the OIM over an uplink optical fiber link. TheRoF signals received by the OIMs are converted to electrical RF signals,which are then communicated to the HEU and to the appropriate BTS toestablish uplink communications between the client devices and the BTSs.

In one embodiment, calibration of the communication downlinks anduplinks in the optical fiber-based wireless system can be performed tocompensate for losses that may occur therein. For example, the HEUcontroller may be configured to calibrate a downlink gain for thecommunication downlink. The calibration downlink gain may be determinedfor each RAU. The calibration downlink gain may be applied in thedownlink BTS interface and/or for each RAU. The HEU controller may alsobe configured to calibrate an uplink gain for the communication uplink.The calibration uplink gain may be applied in the uplink BTS interfaceand/or for each OIM. The BTS error component of the calibration gainsmay be determined to calibrate BTS interfaces separate from the RAUs andOIMs. The calibration gains may be determined by injecting one or morecalibration signals on the communication downlink and/or communicationuplink. The calibration signal injected on the communication downlinkmay also be used to calibrate the communication uplink, or a separatecalibration signal(s) may be injected on the communication uplink.

Before discussing the various features and their details regarding themicrocontroller or microprocessor-based control system or controllersthat may be provided in components of the system, examples of opticalfiber-based distributed antenna systems are their RF communicationsfunctionalities are first described below with regard to FIGS. 1-23.FIGS. 24-54 are discussed with respect to exemplary controllers thatexecute software instructions to provide various control and reportingfeatures for the optical fiber-based distributed antenna systems thatco-exist or reside along with the RF communication capabilities of theoptical fiber-based distributed antenna systems.

In this regard, FIG. 1 is a schematic diagram of a generalizedembodiment of an optical fiber-based distributed antenna system. In thisembodiment, the system is an optical-fiber-based wireless system 10 thatis configured to create one or more picocells. The optical fiber-basedwireless system 10 includes a head-end unit 20, one or more transponderor remote antenna units (RAUs) 30 and an optical fiber RF communicationlink 36 that optically couples the head-end unit (HEU) 20 to the RAU 30.As discussed in detail below, the optical fiber-based wireless system 10has a picocell 40 that can be substantially centered about the RAU 30.The remote antenna transponder units, or simply “RAUs” 30, form apicocellular coverage area 44. The HEU 20 is adapted to perform or tofacilitate any one of a number of Radio-over-Fiber (RoF) applications,such as radio frequency (RF) identification (RFID), wireless local-areanetwork (WLAN) communication, or cellular phone service. Shown withinthe picocell 40 is a client device 45 in the form of a personalcomputer. The client device 45 includes an antenna 46 (e.g., a wirelesscard) adapted to receive and/or send electromagnetic RF signals.

FIG. 2 is a schematic diagram of an example embodiment of the opticalfiber-based wireless system 10 of FIG. 1. In an example embodiment, theHEU 20 includes a service unit 50 that provides electrical RF servicesignals for a particular wireless service or application. In an exampleembodiment, the service unit 50 provides electrical RF service signalsby passing (or conditioning and then passing) such signals from one ormore outside networks 223, as described below. In a particular exampleembodiment, this includes providing WLAN signal distribution asspecified in the IEEE 802.11 standard, i.e., in the frequency range from2.4 to 2.5 GHz and from 5.0 to 6.0 GHz. In another example embodiment,the service unit 50 provides electrical RF service signals by generatingthe signals directly. In another example embodiment, the service unit 50coordinates the delivery of the electrical RF service signals betweenclient devices within the picocellular coverage area 44.

The service unit 50 is electrically coupled to an electrical-to-optical(E/O) converter 60 that receives an electrical RF service signal fromthe service unit and converts it to a corresponding RoF signal, asdiscussed in further detail below. RoF refers to a technology wherebylight is modulated by an electrical RF signal and transmitted over anoptical fiber link to facilitate wireless access. For example, adata-carrying RF signal at a given frequency is imposed on a lightwavesignal before being transported over an optical link. Therefore,wireless signals are optically distributed at the given frequency andconverted from the optical to the electrical domain before beingamplified and radiated by an antenna. As a result, no frequency up/downconversion is required, thereby resulting in simple and rathercost-effective implementations. Advantages of RoF include reducedattenuation of the RF signal over an optical medium when compared towireless medium, and further travel of the RF signal without the needfor as many repeaters. Further, because optical fibers are designed tohandle Gigabit data rates, RoF implementations will be easily adapted inthe future for higher speed networks with protocol and bit-ratetransparency.

In an example embodiment, the E/O converter 60 includes a laser suitablefor delivering sufficient dynamic range for the RoF applications, andoptionally includes a laser driver/amplifier electrically coupled to thelaser. Examples of suitable lasers for the E/O converter 60 includelaser diodes, distributed feedback (DFB) lasers, Fabry-Perot (FP)lasers, and vertical cavity surface emitting lasers (VCSELs).

The HEU 20 also includes an optical-to-electrical (O/E) converter 62electrically coupled to service unit 50. The O/E converter 62 receivesan optical RF service signal and converts it to a correspondingelectrical signal. In an example embodiment, the O/E converter 62 is aphotodetector, or a photodetector electrically coupled to a linearamplifier. The E/O converter 60 and the O/E converter 62 constitute a“converter pair” 66.

In an example embodiment, the service unit 50 includes an RF signalmodulator/demodulator unit 70 that generates an RF carrier of a givenfrequency and then modulates RF signals onto the carrier. Themodulator/demodulator unit 70 also demodulates received RF signals. Theservice unit 50 also includes a digital signal processing unit (“digitalsignal processor”) 72, a central processing unit (CPU) 74 for processingdata and otherwise performing logic and computing operations, and amemory unit 76 for storing data, such as system settings and statusinformation, RFID tag information, etc. In an example embodiment, thedifferent frequencies associated with the different signal channels arecreated by the modulator/demodulator unit 70 generating different RFcarrier frequencies based on instructions from the CPU 74. Also, asdescribed below, the common frequencies associated with a particularcombined picocell are created by the modulator/demodulator unit 70generating the same RF carrier frequency.

With continuing reference to FIG. 2, in an example embodiment a RAU 30includes a converter pair 66, wherein the E/O converter 60 and the O/Econverter 62 therein are electrically coupled to an antenna system 100via a RF signal-directing element 106, such as a circulator. The RFsignal-directing element 106 serves to direct the downlink and uplinkelectrical RF service signals, as discussed below. In an exampleembodiment, the antenna system 100 includes one or more patch antennas,such as disclosed in U.S. patent application Ser. No. 11/504,999entitled “Radio-Over-Fiber Transponder With A Dual-Band Patch AntennaSystem” and filed on Aug. 16, 2006, which patent application isincorporated herein by reference.

RAUs 30 differ from the typical access point device associated withwireless communication systems in that the preferred embodiment of theRAU 30 has just a few signal-conditioning elements and no digitalinformation processing capability. Rather, the information processingcapability is located remotely in the HEU 20, and in a particularexample, in the service unit 50. This allows the RAU 30 to be verycompact and virtually maintenance free. In addition, the preferredexample embodiment of the RAU 30 consumes very little power, istransparent to RF signals, and does not require a local power source, asdescribed below.

With reference again to FIG. 2, an example embodiment of the opticalfiber RF communication link 36 includes a downlink optical fiber 136Dhaving an input end 138 and an output end 140, and an uplink opticalfiber 136U having an input end 142 and an output end 144. The downlinkand uplink optical fibers 136D and 136U optically couple the converterpair 66 at the HEU 20 to the converter pair 66 at the RAU 30.Specifically, the downlink optical fiber input end 138 is opticallycoupled to the E/O converter 60 of the HEU 20, while the output end 140is optically coupled to the O/E converter 62 at the RAU 30. Similarly,the uplink optical fiber input end 142 is optically coupled to the E/Oconverter 60 of the RAU 30, while the output end 144 is opticallycoupled to the O/E converter 62 at the HEU 20.

In an example embodiment, the optical fiber-based wireless system 10employs a known telecommunications wavelength, such as 850 nm, 1300 nm,or 1550 nm. In another example embodiment, the optical fiber-basedwireless system 10 employs other less common but suitable wavelengthssuch as 980 nm.

Example embodiments of the optical fiber-based wireless system 10include either single-mode optical fiber or multi-mode optical fiber fordownlink and the uplink optical fibers 136D and 136U. The particulartype of optical fiber depends on the application of the opticalfiber-based wireless system 10. For many in-building deploymentapplications, maximum transmission distances typically do not exceed 300meters. The maximum length for the intended RF-over-fiber transmissionneeds to be taken into account when considering using multi-mode opticalfibers for the downlink and uplink optical fibers 136D and 136U. Forexample, it has been shown that a 1400 MHz·km multi-mode fiberbandwidth-distance product is sufficient for 5.2 GHz transmission up to300 m.

In an example embodiment, a 50 μm multi-mode optical fiber is used forthe downlink and uplink optical fibers 136D and 136U, and the E/Oconverters 60 operate at 850 nm using commercially available VCSELsspecified for 10 Gb/s data transmission. In a more specific exampleembodiment, OM3 50 μm multi-mode optical fiber is used for the downlinkand uplink optical fibers 136D and 136U.

The optical fiber-based wireless system 10 also includes a power supply160 that generates an electrical power signal 162. The power supply 160is electrically coupled to the HEU 20 for powering the power-consumingelements therein. In an example embodiment, an electrical power line 168runs through the HEU 20 and over to the RAU 30 to power the E/Oconverter 60 and O/E converter 62 in the converter pair 66, the optionalRF signal-directing element 106 (unless element 106 is a passive devicesuch as a circulator), and any other power-consuming elements (notshown). In an example embodiment, the electrical power line 168 includestwo wires 170 and 172 that carry a single voltage and that areelectrically coupled to a DC power converter 180 at the RAU 30. The DCpower converter 180 is electrically coupled to the E/O converter 60 andthe O/E converter 62, and changes the voltage or levels of theelectrical power signal 162 to the power level(s) required by thepower-consuming components in the RAU 30. In an example embodiment, theDC power converter 180 is either a DC/DC power converter, or an AC/DCpower converter, depending on the type of electrical power signal 162carried by the electrical power line 168. In an example embodiment, theelectrical power line 168 includes standard electrical-power-carryingelectrical wire(s), e.g., 18-26 AWG (American Wire Gauge) used instandard telecommunications and other applications. In another exampleembodiment, the electrical power line 168 (dashed line) runs directlyfrom the power supply 160 to the RAU 30 rather than from or through theHEU 20. In another example embodiment, the electrical power line 168includes more than two wires and carries multiple voltages. In anexample embodiment, the HEU 20 is operably coupled to an outside network223 via a network link 224.

With reference to the optical fiber-based wireless system 10 of FIG. 1and FIG. 2, the service unit 50 generates an electrical downlink RFservice signal SD (“electrical signal SD”) corresponding to itsparticular application. In an example embodiment, this is accomplishedby the digital signal processor 72 providing the RF signalmodulator/demodulator unit 70 with an electrical signal (not shown) thatis modulated onto an RF carrier to generate a desired electrical signalSD. The electrical signal SD is received by the E/O converter 60, whichconverts this electrical signal into a corresponding optical downlink RFservice signal SD′ (“optical signal SD′”), which is then coupled intothe downlink optical fiber 136D at the input end 138. It is noted herethat in an example embodiment, the optical signal SD′ is tailored tohave a given modulation index. Further, in an example embodiment, themodulation power of the E/O converter 60 is controlled (e.g., by one ormore gain-control amplifiers, not shown) to vary the transmission powerfrom the antenna system 100. In an example embodiment, the amount ofpower provided to the antenna system 100 is varied to define the size ofthe associated picocell 40, which in example embodiments ranges anywherefrom about a meter across to about twenty meters across.

The optical signal SD′ travels over the downlink optical fiber 136D tothe output end 140, where it is received by the O/E converter 62 in RAU30. The O/E converter 62 converts the optical signal SD′ back into anelectrical signal SD, which then travels to the RF signal-directingelement 106. The RF signal-directing element 106 then directs theelectrical signal SD to the antenna 100. The electrical signal SD is fedto the antenna system 100, causing it to radiate a correspondingelectromagnetic downlink RF service signal SD″ (“electromagnetic signalSD″”).

Because the client device 45 is within the picocell 40, theelectromagnetic signal SD″ is received by the client device antenna 46,which may be part of a wireless card, or a cell phone antenna, forexample. The antenna 46 converts the electromagnetic signal SD″ into anelectrical signal SD in the client device (signal SD is not showntherein). The client device 45 then processes the electrical signal SD,e.g., stores the signal information in memory, displays the informationas an e-mail or text message, or other display of information, etc. Theclient device 45 can generate electrical uplink RF signals SU (not shownin the client device 45), which are converted into electromagneticuplink RF service signals SU″ (electromagnetic signal SU””) by theantenna 46.

Because the client device 45 is located within the picocell 40, theelectromagnetic signal SU″ is detected by the antenna system 100 in theRAU 30, which converts this signal back into an electrical signal SU.The electrical signal SU is directed by the RF signal-directing element106 to the E/O converter 60, which converts this electrical signal intoa corresponding optical uplink RF service signal SU′ (“optical signalSU′”), which is then coupled into the input end 142 of the uplinkoptical fiber 136U. The optical signal SU′ travels over the uplinkoptical fiber 136U to the output end 144, where it is received by theO/E converter 62 at the HEU 20. The O/E converter 62 converts theoptical signal SU′ back into electrical signal SU, which is thendirected to the service unit 50. The service unit 50 receives andprocesses the electrical signal SU, which in an example embodimentincludes one or more of the following: storing the signal information;digitally processing or conditioning the signals; sending the signals toone or more outside networks 223 via network links 224; and sending thesignals to one or more client devices 45 in the picocellular coveragearea 44. In an example embodiment, the processing of the electricalsignal SU includes demodulating this electrical signal SU in the RFsignal modulator/demodulator unit 70, and then processing thedemodulated signal in the digital signal processor 72.

FIG. 3 is a schematic diagram of an example embodiment of an opticalfiber-based wireless system 200 that includes a central HEU 210. Thecentral HEU 210 can be thought of as a HEU 20 adapted to handle one ormore service units 50 and one or more RAUs 30. The central HEU 210 isoptically coupled to an optical fiber cable 220 that includes multipleRAUs 30. The optical fiber cable 220 is constituted by multiple opticalfiber RF communication links 36 (FIG. 2), with each link opticallycoupled to a corresponding RAU 30. In an example embodiment, multipleRAUs 30 are spaced apart along the length of optical fiber cable 220(e.g., at eight (8) meter intervals) to create a desired picocellcoverage area 44 made up of picocells 40, which may overlap at theiredges.

FIG. 4 is a detailed schematic diagram of an example embodiment of thecentral HEU 210. Rather than including multiple HEUs 20 of FIG. 1directly into the central HEU 210, in an example embodiment the HEUs 20are modified to allow for each service unit 50 to communicate with one,some, or all of RAUs 30, depending on the particular application of agiven service unit 50. The service units 50 are each electricallycoupled to an RF transmission line 230 and an RF receiving line 232. InFIG. 4, only three of six service units 50A through 50F are shown forthe purposes of clarity of illustration.

In an example embodiment, the optical fiber-based wireless system 200further includes a main controller 250 operably coupled to the serviceunits 50 and adapted to control and coordinate the operation of theservice units 50 in communicating with the RAUs 30. In an exampleembodiment, the main controller 250 includes a central processing unit(CPU) 252 and a memory unit 254 for storing data. The CPU 252 is adapted(e.g., is programmed) to process information provided to the maincontroller 250 by one or more of the service units 50. In an exampleembodiment, the main controller 250 is or includes a programmablecomputer adapted to carry out instructions (programs) provided to it orotherwise encoded therein on a computer-readable medium.

The central HEU 210 further includes a downlink RF signal multiplexer(“downlink multiplexer”) 270 operably coupled to the main controller250. The downlink multiplexer 270 has an input side 272 and an outputside 274. RF transmission lines 230 are electrically connected to thedownlink multiplexer 270 at the input side 272.

In an example embodiment, the downlink multiplexer 270 includes an RFsignal-directing element 280 (e.g., a RF switch) that allows forselective communication between the service units 50 and the RAUs 30, asdescribed below. In an example, the selective communication involvessequentially addressing RAUs 30 for polling corresponding picocells 40.Such sequential polling can be used, for example, when one of theservice units 50 is an RFID reader searching for RFID tags 290 inpicocells 40 (FIG. 3). In an example embodiment, the RFID tags 290 areattached to an item 292 (FIG. 3) to be tracked or otherwise monitoredvia the attached RFID tag 290. In another example embodiment, theselective communication involves simultaneously addressing some or allof the RAUs 30. Such simultaneous addressing can be used, for example,when one of the service units 50 is a cellular phone transmitter or anRF-signal feed-through unit that provides simultaneous coverage of someor all of the picocells 40.

The central HEU 210 also includes an uplink RF signal multiplexer(“uplink multiplexer”) 320 operably coupled to the main controller 250and having an input side 322 and an output side 324. Receiving lines 232are electrically connected to the uplink multiplexer 320 at the outputside 324. In an example embodiment, the uplink multiplexer 320 includesan RF signal-directing element 328.

The central HEU 210 also includes a number of E/O converters 60 thatmake up an E/O converter array 360, and a corresponding number of O/Econverters 62 that make up an O/E converter array 362. The E/Oconverters 60 are electrically coupled to the output side 274 ofdownlink multiplexer 270 via electrical lines 330, and are opticallycoupled to the input ends 138 of corresponding downlink optical fibers136D. The O/E converters 62 are electrically coupled to the input side322 of the uplink multiplexer 320 via electrical lines 332, and areoptically coupled to the output ends 144 of corresponding uplink opticalfibers 136U. The downlink optical fibers 136D constitute a downlinkoptical fiber cable 378 and the uplink optical fibers 136U constitute anuplink optical fiber cable 380.

FIG. 5A is a close-up schematic diagram of optical fiber cable 220showing downlink and uplink optical fibers 136D and 136U and two of thesix RAUs 30. Also shown is the electrical power line 168 electricallycoupled to the RAUs 30. In an example embodiment, the optical fibercable 220 includes a protective outer jacket 344. In an exampleembodiment, the RAUs 30 reside completely within the protective outerjacket 344. FIG. 5B is a schematic diagram similar to FIG. 5A,illustrating an example embodiment wherein the RAUs 30 lie outside ofthe protective outer jacket 344. Locating the RAUs 30 outside of theprotective outer jacket 344 makes it easier to arrange the RAUs 30relative to a building infrastructure after the optical fiber cable 220is deployed, as described below.

With reference to FIGS. 3, 4, 5A and 5B, the optical fiber-basedwireless system 200 operates as follows. At the central HEU 210, theservice units 50A, 50B, . . . 50F each generate or pass through from oneor more outside networks 223 respective electrical signals SD thatcorrespond to the particular application of the given service unit 50.The electrical signals SD are transmitted over the RF transmission lines230 to the downlink multiplexer 270. The downlink multiplexer 270 thencombines (in frequency) and distributes the various electrical signalsSD to the E/O converters 60 in the E/O converter array 360. In anexample embodiment, the downlink multiplexer 270 and RF signal-directingelement 280 therein are controlled by the main controller 250 via acontrol signal 51 (not shown) to the direct electrical signals SD toone, some or all of the E/O converters 60 in the E/O converter array 360and thus to one, some or all of the RAUs 30, based on the particularservice unit application. For example, if service unit 50A is a cellularphone unit, then in an example embodiment the electrical signals SDtherefrom (e.g., passing therethrough from one or more outside networks223) are divided (and optionally amplified) equally by the RFsignal-directing element 280 and provided to each E/O converter 60 inthe E/O converter array 360. This results in each RAU 30 beingaddressed. On the other hand, if the service unit 50F is a WLAN serviceunit, then the RF signal-directing element 280 may be adapted (e.g.,programmed) to direct electrical signals SD to select ones of E/Oconverters 60 in E/O converter array 360 so that only select RAUs 30 areaddressed.

Thus, one, some, or all of the E/O converters 60 in the E/O converterarray 360 receive the electrical signals SD from the downlinkmultiplexer 270. The addressed E/O converters 60 in the E/O converterarray 360 convert the electrical signals SD into corresponding opticalsignals SD′, which are transmitted over the corresponding downlinkoptical fibers 136D to the corresponding RAUs 30. The addressed RAUs 30convert the optical signals SD′ back into electrical signals SD, whichare then converted into electromagnetic signals SD″ that correspond tothe particular service unit application.

FIG. 6 is a close-up view of one of the RAUs 30, illustrating thecorresponding picocell 40 and the exchange of downlink and uplinkelectromagnetic signals SD″ and SU″ between the RAU 30 and clientdevices 45 within the picocell 40. In particular, the electromagneticsignals SU″ are received by the corresponding RAU 30 and converted toelectrical signals SU, and then to optical signals SD′. The opticalsignals SD′ then travel over the uplink optical fiber 136U and arereceived by the O/E converter array 362 and the corresponding O/Econverters 62 therein for the addressed RAUs 30. The O/E converters 62convert the optical signals SU′ back to electrical signals SU, whichthen proceed to the uplink multiplexer 320. The uplink multiplexer 320then distributes the electrical signals SU to the service unit(s) 50that require(s) receiving these electrical signals. The receivingservice units 50 process the electrical signals SU, which in an exampleembodiment includes one or more of: storing the signal information;digitally processing or conditioning the signals; sending the signals onto one or more outside networks 223 via the network links 224; andsending the signals to one or more client devices 45 in the picocellularcoverage area 44.

In an example embodiment, the uplink multiplexer 320 and the RFsignal-directing element 328 therein are controlled by the maincontroller 250 via a control signal S2 (FIG. 4) to direct electricalsignals SU to the service unit(s) 50 that require(s) receivingelectrical signals SU. Different services from some or all of theservice units 50 (i.e. cellular phone service, WiFi for datacommunication, RFID monitoring, etc.) may be combined at the RF signallevel by frequency multiplexing.

In an example embodiment, a single electrical power line 168 from thepower supply 160 at central HEU 210 is incorporated into the opticalfiber cable 220 and is adapted to power each RAU 30, as shown in FIG. 6.Each RAU 30 taps off the needed amount of power, e.g., via a DC powerconverter 180 (FIG. 2). Since the preferred embodiment of a RAU 30 hasrelatively low functionality and power consumption, only relatively lowelectrical power levels are required (e.g., ˜1 watt), allowinghigh-gauge wires to be used (e.g., 20 AWG or higher) for the electricalpower line 168. In an example embodiment that uses many RAUs 30 (e.g.,more than twelve (12)) in the optical fiber cable 220, or if the powerconsumption for the RAUs 30 is significantly larger than 1 watt due totheir particular design, lower gauge wires or multiple wires areemployed in the electrical power line 168. The inevitable voltage dropalong the electrical power line 168 within the optical fiber cable 220typically requires large-range (˜30 volts) voltage regulation at eachRAU 30. In an example embodiment, DC power converters 180 at each RAU 30perform this voltage regulation function. If the expected voltage dropis known, then in an example embodiment the main controller 250 carriesout the voltage regulation. In an alternative embodiment, remote voltagesensing at each RAU 30 is used, but this approach is not the preferredone because it adds complexity to the system.

FIG. 7 is a schematic diagram of an example embodiment of a centralizedoptical fiber-based wireless system 400. The centralized opticalfiber-based wireless system 400 is similar to the optical fiber-basedwireless system 200 as described above, but includes multiple opticalfiber cables 220 optically coupled to the central HEU 210. The centralHEU 210 includes a number of E/O converter arrays 360 and acorresponding number of O/E converter arrays 362, arranged in pairs inconverter array units 410, with one converter array unit 410 opticallycoupled to one optical fiber cable 220. Likewise, the centralizedoptical fiber-based wireless system 400 includes a number of downlinkmultiplexers 270 and uplink multiplexers 320, arranged in pairs inmultiplexer units 414, with one multiplexer unit 414 electricallycoupled to one converter array unit 410. In an example embodiment, themain controller 250 is electrically coupled to each multiplexer unit 414and is adapted to control the operation of the downlink and uplinkmultiplexers 270 and 320 therein. Here, the term “array” is not intendedto be limited to components integrated onto a single chip as is oftendone in the art, but includes an arrangement of discrete, non-integratedcomponents.

Each E/O converter array 360 is electrically coupled to the downlinkmultiplexer 270 in the corresponding multiplexer unit 414. Likewise,each O/E converter array 362 is electrically coupled to the uplinkmultiplexer 320 in the corresponding multiplexer unit 414. The serviceunits 50 are each electrically coupled to both downlink and uplinkmultiplexers 270 and 320 within each multiplexer unit 414. Respectivedownlink and uplink optical fiber cables 378 and 380 optically coupleeach converter array unit 410 to a corresponding optical fiber cable220. In an example embodiment, the central HEU 210 includes connectorports 420 and the optical cables 220 include connectors 422 adapted toconnect to the connector ports 420. In an example embodiment, theconnectors 422 are MT (“Mechanical Transfer”) connectors, such as theUNICAM® MTP connector available from Corning Cable Systems, Inc.,Hickory, N.C. In an example embodiment, the connectors 422 are adaptedto accommodate the electrical power line 168 connected to the connectorport 420.

FIG. 8 is a “top down” view of the centralized optical fiber-basedwireless system 400, showing an extended picocellular coverage area 44formed by using multiple optical fiber cables 220. In an exampleembodiment, the centralized optical fiber-based wireless system 400supports anywhere from two RAUs 30, to hundreds of RAUs 30, to eventhousands of RAUs 30. The particular number of RAUs 30 employed is notfundamentally limited by the design of the centralized opticalfiber-based wireless system 400, but rather by the particularapplication.

In FIG. 8, the picocells 40 are shown as non-overlapping. Thisnon-overlap is based on adjacent RAUs 30 operating at slightly differentfrequencies to avoid the otherwise undesirable substantial overlap thatoccurs between adjacent picocells that operate at the same frequency.Same-frequency overlap is discussed in greater detail below inconnection with embodiments that combine two or more picocells.

The optical fiber-based wireless system 400 operates in a manner similarto the optical fiber-based wireless system 200 as described above,except that instead of the RAUs 30 being in a single optical fiber cable220, they are distributed over two or more optical fiber cables 220through the use of corresponding two or more converter array units 410.Electrical signals SD from the service units 50 are distributed to eachmultiplexer unit 414. The downlink multiplexers 270 therein conveyelectrical signals SD to one, some, or all of the converter array units410, depending on which RAUs 30 are to be addressed by which serviceunit 50. Electrical signals SD are then processed as described above,with downlink optical signals SD′ being sent to one, some or all of RAUs30. Uplink optical signals SU′ generated by client devices 45 in thecorresponding picocells 40 return to the corresponding converter arrayunits 410 at the central HEU 210. The optical signals SU′ are convertedto electrical signals SU at the receiving converter array unit(s) 410and are then sent to the uplink multiplexers 320 in the correspondingmultiplexer unit(s) 414. The uplink multiplexers 320 therein are adapted(e.g., programmed by the main controller 250) to direct electricalsignals SU to the service unit(s) 50 that require(s) receivingelectrical signals SU. The receiving service units 50 process theelectrical signals SU, which as discussed above in an example embodimentincludes one or more of storing the signal information; digitallyprocessing or conditioning the signals; sending the signals to one ormore outside networks 223 via network links 224; and sending the signalsto one or more client devices 45 in the picocellular coverage area 44.

FIG. 9A is a schematic cut-away diagram of a building infrastructure 500that generally represents any type of building in which an opticalfiber-based wireless system would be useful, such as office buildings,schools, hospitals, college buildings, airports, warehouses, etc. Thebuilding infrastructure 500 includes a first (ground) floor 501, asecond floor 502, and a third floor 503. The first floor 501 is definedby a floor 510 and a ceiling 512; the second floor 502 is defined by afloor 520 and a ceiling 522; and the third floor 503 is defined by afloor 530 and a ceiling 532. An example centralized optical fiber-basedwireless system 400 is incorporated into the building infrastructure 500to provide a picocellular coverage area 44 that covers floors 501, 502and 503.

In an example embodiment, the centralized optical fiber-based wirelesssystem 400 includes a main cable 540 having a number of differentsections that facilitate the placement of a large number of RAUs 30 inthe building infrastructure 500. FIG. 9A is a schematic diagram of anexample embodiment of the main cable 540. The main cable 540 is alsoillustrated by example in FIG. 9B. As illustrated therein, the maincable 540 includes a riser section 542 that carries all of the uplinkand downlink optical fiber cables 378 and 380 from the central HEU 210.The cable main 540 includes one or more multi-cable (MC) connectors 550adapted to connect select downlink and uplink optical fiber cables 378and 380, along with the electrical power line 168, to a number ofoptical fiber cables 220. In an example embodiment, MC connectors 550include individual connector ports 420, and optical fiber cables 220include matching connectors 422. In an example embodiment, the risersection 542 includes a total of seventy-two (72) downlink andseventy-two (72) uplink optical fibers 136D and 136U, while twelve (12)optical fiber cables 220 each carry six (6) downlink and six (6) uplinkoptical fibers.

The main cable 540 enables multiple optical fiber cables 220 to bedistributed throughout the building infrastructure 500 (e.g., fixed tothe ceilings 512, 522 and 532) to provide an extended picocellularcoverage area 44 for the first, second and third floors 501, 502 and503. An example type of MC connector 550 is a “patch panel” used toconnect incoming and outgoing optical fiber cables in an opticaltelecommunication system.

In an example embodiment of the multi-section main cable 540, theelectrical power line 168 from the power supply 160 runs from thecentral HEU 210 through the riser section 542 and branches out into theoptical fiber cables 220 at the MC connectors 550 (FIG. 8). In analternative example embodiment, electrical power is separately suppliedat each MC connector 550, as indicated by the dashed-box power supplies160 and dashed-line electrical power lines 168 illustrated in FIGS. 9Aand 9B.

In an example embodiment, the central HEU 210 and the power supply 160are located within the building infrastructure 500 (e.g., in a closet orcontrol room), while in another example embodiment one or both arelocated outside of the building at a remote location.

An example embodiment involves tailoring or designing the picocellularcoverage areas 44 for the different floors to suit particular needs.FIG. 10 is a schematic “top down” view of the second floor 502 of thebuilding infrastructure 500, showing three optical fiber cables 220branching out from the MC connector 550 and extending over the ceiling532 (FIG. 10). The MC connectors 550 include connector ports 560 and thethree optical cables 220 include connectors 562 adapted to connect tothe connector ports 560 in this embodiment. The picocells 40 associatedwith RAUs 30 (not shown in FIG. 10) form an extended picocellularcoverage area 44 that covers the second floor 502 with fewer, largerpicocells than the first and third floors 501 and 503 (FIG. 9A). Suchdifferent picocellular coverage areas 44 may be desirable when thedifferent floors have different wireless needs. For example, the thirdfloor 503 might require relatively dense picocell coverage if it servesas storage for items that need to be inventoried and tracked via RFIDtags 290 (FIG. 3), which can be considered simple client devices 45.Likewise, the second floor 502 may be office space that calls for largerand fewer picocells to provide cellular phone service and WLAN coverage.

FIG. 11A is a schematic diagram of an example embodiment of an opticalfiber-based wireless system 600 incorporating multiple HEUs or stations610 to provide various types of wireless service to a coverage area.FIG. 11B is a partially schematic cut-away diagram of a buildinginfrastructure 620 that generally represents any type of building inwhich the optical fiber-based wireless system 600 might be used. This,the optical fiber-based wireless system 600 in this embodiment can be anin-door distributed antenna system (IDAS) to provide wireless serviceinside a building. In the embodiment discussed below, the servicesprovided can be cellular service, wireless services such as RFIDtracking, WiFi, LAN, combinations thereof, etc. FIG. 11B illustrates thecoverage provided by a single HEU 610 and associated system components,although a building infrastructure can be served by multiple HEUs 610comprising part of a optical fiber-based wireless system 600 as shownschematically in FIG. 11A.

Referring first to FIG. 11B, the building infrastructure 620 includes afirst (ground) floor 601, a second floor 602, and a third floor 603. Thefloors 601, 602, 603 are serviced by the HEU 610, through a maindistribution frame 612, to provide a coverage area 630 in the buildinginfrastructure 620. Only the ceilings of the floors 601, 602, 603 areshown in FIG. 11B for simplicity of illustration. In the exampleembodiment, a main cable 640 has a number of different sections thatfacilitate the placement of a large number of RAUs 650 in the buildinginfrastructure 620. Each RAU 650 in turn services its own coverage areain the coverage area 630. The main cable 640 can have, for example, theconfiguration as shown generally in FIG. 11, and can include a risersection 642 that carries all of the uplink and downlink optical fibercables to and from the HEU 610. The main cable 640 can include one ormore multi-cable (MC) connectors adapted to connect select downlink anduplink optical fiber cables, along with an electrical power line, to anumber of optical fiber cables 644. In an example embodiment, aninterconnect unit 660 is provided for each floor 601, 602, and 603, theinterconnect units 660 including an individual passive fiberinterconnection of optical fiber cable ports. The optical fiber cables644 include matching connectors. In an example embodiment, the risersection 642 includes a total of thirty-six (36) downlink and thirty-six(36) uplink optical fibers, while each of the six (6) optical fibercables 644 carries six (6) downlink and six uplink optical fibers toservice six (6) RAUs 650. The number of optical fiber cables 644 can bevaried to accommodate different applications, including the addition ofsecond, third, etc. HEUs 610.

According to one aspect, each interconnect unit 660 can provide a lowvoltage DC current to the electrical conductors in the optical fibercables 644 for powering the RAUs 650. For example, the interconnectunits 660 can include an AC/DC transformer to transform 110V AC powerthat is readily available in the building infrastructure 620. In oneembodiment, the transformers supply a relatively low voltage DC currentof 48V or less to the optical fiber cables 644. An uninterrupted powersupply could be located at the interconnect units 660 and at the HEU 610to provide operational durability to the optical fiber-based wirelesssystem 600. The optical fibers utilized in the optical fiber cables 644can be selected based upon the type of service required for the system,and single mode and/or multi-mode fibers may be used.

The main cable 640 enables multiple optical fiber cables 644 to bedistributed throughout the building infrastructure 620 (e.g., fixed tothe ceilings or other support surfaces of each floor 601, 602 and 603)to provide the coverage area 630 for the first, second and third floors601, 602 and 603. In an example embodiment, the HEU 610 is locatedwithin the building infrastructure 620 (e.g., in a closet or controlroom), while in another example embodiment it may be located outside ofthe building at a remote location. A base transceiver station (BTS) 670,which may be provided by a second party such as cellular serviceprovider, is connected to the HEU 610, and can be co-located or locatedremotely from the HEU 610. A BTS is any station or source that providesan input signal to the HEU 610 and can receive a return signal from theHEU 610. In a typical cellular system, for example, a plurality of BTSsare deployed at a plurality of remote locations to provide wirelesstelephone coverage. Each BTS serves a corresponding cell and when amobile station enters the cell, the BTS communicates with the mobilestation. Each BTS can include at least one radio transceiver forenabling communication with one or more subscriber units operatingwithin the associated cell.

The optical fiber-based wireless system 600 shown schematically in FIG.11A represents essentially six (6), of which only three (3) areillustrated, of the arrangements shown in FIG. 11B interconnected organged as a single system. The optical fiber-based wireless system 600can therefore provide a broader coverage area within a buildinginfrastructure (e.g., covering additional floors). In FIG. 11A, six HEUs610 are connected to the base transceiver station (BTS) 670 via a powersplitter 714. Each optical fiber cable 644 is in turn connected to aplurality of RAUs 650 having an antenna (one RAU 650 is illustrated foreach optical fiber cable 644 for simplicity of illustration), asgenerally illustrated in FIG. 7B. The HEUs 610 are host neutral systemsin this embodiment which can provide services for one or more BTSs 670with the same infrastructure that is not tied to any particular serviceprovider. Each HEU 610 is connected to six (6) optical fiber cables 644(as also shown in FIG. 11B). The exemplary optical fiber-based wirelesssystem 600 therefore includes two hundred sixteen (216) RAUs 650, witheach of the six (6) HEUs 610 being connected to thirty-six (36) RAUs650, although fewer or more HEUs 610, optical fiber cables 644 and RAUs650 may be included depending upon the desired coverage area. Forexample, fewer than six (6) HEUs 610 can be employed to obtain the samecoverage capability as in FIG. 11A by increasing the capacity of eachHEU 610 to support RAUs 650. Each optical fiber cable 644 may include anelectrical power line running between its associated HEUs 610 and theRAUs 650 connected to the optical fiber cable 644, and/or power may besupplied at the interconnect units 660. In the illustrated embodiment,power is supplied at the interconnect units 660. The RAUs 650 can belocated outside of the protective outer jacket of the optical fibercables 644 so that it is easier to arrange the RAUs 650 relative to abuilding infrastructure after the optical fiber cable 644 is deployed,as discussed above.

FIG. 12A is a schematic diagram of an exemplary HEU 610. In theillustrated embodiment, the HEU 610 includes a processing section 742that manages the functions of the unit components and communicates withexterior devices via the CIF. The HEU 610 can be connected to aplurality of base transceiver stations, transceivers, etc. atconnections 744, 746. The connections 744 are downlink connections andconnections 746 are uplink connections. Each downlink connection 744 isconnected to a downlink BTS interface card (BIC) 754 located in the HEU610, and each uplink connection 746 is connected to an uplink BIC 756also located in the HEU 610. The downlink BIC 754 is connected to acoaxial connector panel 760, which can be in the form of a midplanepanel, by cables 758. The uplink BIC 756 is also connected to thecoaxial connector panel 760 by cables 758. The coaxial connector panel760 is in electrical communication with a plurality of optical interfacemodules (OIM) 770, which are in optical and electrical communicationwith the RAUs 650 via the optical fiber cables 644. The OIMs 770 canplug directly into the coaxial connector panel 760.

Note that the OIMs 770 are shown as supporting up to six RAUs 650, butthe OIMs 770 in this embodiment consist of two optical interface card(OICs) each supporting up to three RAUs 650 each. This is furtherillustrated in alternative exemplary HEU 610′ in FIG. 12B. Asillustrated therein, two OICs 771 are provided for each OIM 770. Amidplane interface card 747 can be deployed in the HEU 610′ to interfacethe DL-BIC 754 and UL-BIC 756 to the OICs 771. A head-end controller(HEC) 773 is also included in the HEU 610′ that is configured tocommunicate with the DL-BIC 754, the UL-BIC 756, the OICs 770 and theRAUs 771 to monitor, configure, and perform other tasks for thesecomponents, as will be described in more detail in this application.Several ports can be provided to allow external interfacing to the HEC773 including but not limited to a RS-232 serial port 775, a universalserial bus (USB) port 777, and an Ethernet port 779. These ports allowfor external information exchange with the HEC 773, such as forproviding commands to the HEC 773 to configuring the DL-BIC 754, theUL-BIC 756, the OICs 770 and the RAUs 771 and receiving informationregarding the monitoring and status of the DL-BIC 754, the UL-BIC 756,the OICs 770 and the RAUs 771.

FIG. 13 is a front exterior view and FIG. 14 is a rear exterior view ofa HEU 610. FIG. 13 illustrates the OIMs 770 and connectors 774 used toconnect to the RAUs 650 assigned to each OIM 770. As also illustrated inFIGS. 11B and 12, each OIM 770 connects to six (6) optical fiber cables644 at the connections 744. FIG. 13 also shows the orientation of aswitch 778 and a processing section 742 in HEC 773 of the HEU 610. Aswill be described in more detail below, the processing section 742includes a software-based microprocessor to configure and monitor thecomponents of the HEU 610 and the RAUs 771. The switch 778 is providedto allow additional HEUs 610 to be connected to the HEU 610 in a slavearrangement to allow the HEU 610, as a master unit, to control andprovide access to additional OIMs 770 and RAUs 771, as will be describedin more detail below. Alternatively, the switch 778 and the processingsection 742 may be included in a separate board or module from the HEC773. The processing section 742 can be, for example, a commerciallyavailable computer such as the EP440C single board computer availablefrom Embedded Planet of Warrensville, Ohio. The processing section 742can include components such as DDR memory interfaces, and integratedEthernet, USB, UART, I2C, SPI, and PCI interfaces. FIG. 14 illustratesthe connections 744, 746 on the downlink and uplink BICs 754, 756 and apower supply 788 for the HEU 610. In the illustrated embodiment, thepower supply 788 is a model MPS-200 available from Astrodyne.

FIG. 15A is a schematic diagram of an OIM 770 comprised of an OIC 771that supports up to six (6) RAUs 650 on a single printed circuit board(PCB). FIG. 15B illustrates an OIM 770′ comprising an OIC 771′ thatsupports up to three (3) RAUs 650 on a single PCB. Two OICs 771′ may bepackaged together in a common chassis (not shown) to provide the samefunction of the OIM 770 of FIG. 15A. The OIC 771′ in FIG. 15B containssimilar components to the OIC 771 and thus the OIC 770′ will bediscussed as equally applicable to the OIC 771′ in FIG. 15B with commonelement numbers shared between the two. A computer management system(CMS) interface 813 is provided to connect the OIM 770 to a port on themid-plane interface card 747 to connect the OIM 770 to the DL-BIC 754and UL-BIC 756, as illustrated in FIG. 12B, as will be described in moredetail below. The CMS interface 813 provides access to the internal busthat allows communication between the HEU 773 and DL-BIC 754, the UL-BIC756, the OIMs 770 and RAUs 771 as will be described in more detailbelow.

As illustrated in FIG. 15A, the OIC 770′ comprises a six-way downlinksplitter 814 electrically coupled to an uplink coaxial connection 771, asix-way uplink combiner 816 electrically coupled to a downlink coaxialconnection 772, six downlinks 818, six uplinks 820, six E/O converters824, six O/E converters 826, and connectors 774. As illustrated, eachOIC 770′ is designed to support at least six RAUs 650. The number ofRAUs 650 can be varied, however, depending upon the particularapplication. In the illustrated embodiment, the connectors 774 are dualSC/APC interfaces. Referring also to FIG. 16A, the downlink splitter 814divides an RF electrical downlink signal into multiple RF electricalsignals, as desired, each being forwarded to a multi-band downlink 818,which filters the RF signal into a number of desired separate bands. Ifthe optical fiber-based wireless system 600 is used to provide cellphone service alone, for example, the 3-band downlink 818 can be used.If the optical fiber-based wireless system 600 is to be used to supportother and/or additional services, such as WiFi, LAN, etc., the HEU 610can be adapted to accommodate the required bands. The filtered signalsfrom each multi-band downlink 818 are forwarded to an E/O converter 824,each E/O converter 824 supporting a RAU 650. Each E/O converter 824converts the filtered electrical RF signal into an optical signal foruse by a RAU 650. The combiner 816 receives electrical downlink signalsfrom multi-band downlinks 818, which in turn receive electrical signalsfrom O/E converters 826. Each O/E converter 826 receives optical signalsfrom a RAU 650 and converts it to an electrical signal. As shown in FIG.16A, calibration signals B1, B2, B3 can be inserted into the RF paths ofthe three bands in the multi-band downlink 818. FIG. 17 shows aperspective and an end view of the OIM 770. FIG. 16B illustrates analternative OIC 771 where the downlink splitter 814 does not spilt ofthe RF downlink signal into multiple bands.

FIG. 18A is a schematic diagram of the downlink BIC 754, which cancomprise a single printed circuit board. FIG. 18B illustrates anotherdownlink BIC 754, supporting up to twelve output to OIMs 770 instead ofsix outputs to OIMs 770 as provided in FIG. 18A. The downlink BIC 754receives input signals from the BTS 670, combines the inputs, and thensplits the combined signal into six outputs for use by the OIMs 770.Switching in the downlink BIC 754 can be controlled by the processingsection 742 of the HEU 773 (see FIG. 12B). Further, as illustrated inFIGS. 18A and 18B, the ports of the downlink BIC 754 may be terminatedwhen not in use by a resistor, which in this example is fifty (50) Ohms.Switches under software control may be provided that can be controllablyswitched to couple the resistor to the termination port when not in use.For example, termination may be desired when a port is not in use tominimize or eliminate reflections in the optical paths of thecommunication downlink.

FIG. 19A is a schematic diagram of the uplink BIC 756, which cancomprise a single printed circuit board. The uplink BIC 756 combines theelectrical output signals from up to six (6) OIMs 770 and generates fouroutput signals to the BTS 670. Two calibration filters 837A, 837B areprovided for each output signal to the BTS 670 to filter out each of thetwo frequencies employed for the calibration signal from the outputsignal in this embodiment, as will be described in more detail below.FIG. 19B is a schematic diagram of the uplink BIC 756, which cancomprise a single printed circuit board. The uplink BIC 756 combines theelectrical output signals from up to twelve (12) OIMs 770 and generatesfour output signals to the BTS 670. Further, as illustrated in FIGS. 19Aand 19B, the ports of the uplink BIC 756 may also be terminated when notin use by a resistor, which in this example is fifty (50) Ohms. Switchesunder software control may be provided that can be controllably switchedto couple the resistor to the termination port when not in use. Forexample, termination may be desired when a port is not in use tominimize or eliminate reflections in the optical paths of thecommunication downlink.

FIG. 20 is a schematic diagram of a RAU 650. The RAUs 650 are theremotely located endpoints for service signal distribution in theoptical fiber-based wireless system's 600 service area. The RAUs 650provide signal conditioning such that client devices can operate as ifthey were communicating with a BTS 670 directly. The illustrated RAU 650includes a connector 830 that interfaces with an antenna system (shownin FIGS. 21 and 22). In an example embodiment, the antenna system 858includes one or more patch antennas, such as disclosed in the previouslyincorporated U.S. patent application Ser. No. 11/504,999. The RAU 650interfaces to the HEU 610 via optical fibers in the optical fiber cables644 that provide the conduit for radio, control signals, etc. andinterfaces with the client device via radio signals. The RAU 650receives downlink signals conveyed by the optical fiber cable 644 sentfrom a HEU 610, where an O/E converter 840 converts the optical signalto an RF electrical signal. An E/O converter 844 converts RF uplink datainto an optical signal forwarded to a HEU 610.

The functions that the RAU 650 may perform include setting the outputpower or gain of the downlink signals, providing signal conditioning forthe uplink to properly interface radio signals to the optical conversionmodule, and providing status information back to a HEU 610. The signalon the optical link can be broadband containing the bands of signalssupported by the optical fiber-based wireless system 600. The RAU 650splits these signals in three and routes them to separate band-limitedcircuits. For each band, the signal path consists of amplifiers, filtersand attenuators that adjust the signal to the proper level at theantenna 858 for transmission. The minimum gain of the signal path may bedetermined from the maximum output power that can be transmitted (+14dBm) and from a minimum desired input power for the multi-band downlink818. For example, to transmit at a level of +14 dBm (composite totalacross the band) Code Division Multiple Access (CDMA) signal formats(which have peak to average power ratios of 10 dB), the output stage ofthe downlink signal must have a one dB compression point of +24 dBm. Theoutput of the amplifier goes through a duplexor that combines the bandsbefore it is transmitted.

The downlink circuitry may have the ability to be turned on or off basedupon the user setup for the optical fiber-based wireless system 600. Itmay be desired to turn off unused circuits, for example, for powerconservation and to also reduce the possibility of interference orcrosstalk between the other frequency bands. The downlink also detectsand measures the calibration signals B1, B2, B3 generated by themulti-band downlink 818 (FIG. 16A). The calibration signals B1, B2, B3are used to calculate the loss of the optical path and also to calculatethe downlink gain. These two measurements are used to control theoverall signal gain/output power from the BTS 670 to the antenna 858 ofthe RAU 650. All of the downlink individual band signals are combinedand interfaced to the antenna 858. The duplexer combines the threedownlink bands as well as interfaces the antenna to the uplinkamplifiers.

The downlink circuitry carries RF communication signals to the E/Oconverter 824 to be communicated to the RAU 650 and to client deviceswireless communicating with the RAUs 650. The uplink circuitryconditions signals received at the antenna 858 from client devices andconverts them to optical signals for transmission to the OIM 770 via theoptical fiber cables 644. The uplink circuitry provides gain for thesignal prior to the optical conversion, injects the calibration signalfor calculation of the uplink gain, and inserts the data communicationssignal. The amount of gain for the uplink amplifiers is set from therequirement for the maximum input signal received by the antenna 858,and also by the maximum signal level that can be input into thetransmitting optical subassembly. The RAU 650 can communicate with theOIM 770 to pass status information to the OIM 770 and to receiveoperational and configuration information from the RAU 650. Anamplitude-modulated signal can be combined with radio signals to allowcommunications between the RAU 650 and the OIM 770. Simple On/Off keyingof the frequency source should provide a low cost and sufficientsolution. The carrier frequency is 10.7 MHz using a standard RS-232protocol. The

FIGS. 21 and 22, respectively, are a perspective view and a side view ofa RAU 650 with the cover of the unit omitted to show the unit interior.The RAU 650 includes a printed circuit board 850 that can support theunit's circuit components, a protective housing 854, and an antenna 858mounted on a bracket 862. An SC duplex adapter 866 mounted on a bracket870 provides optical connectivity. A visual indicator 874 such as alight-emitting diode (LED) can be provided to indicate when the RAU 650is in operation. An RF N-type connector 878 provides RF connectivitybetween the RAU 650 and the antenna 858. A universal serial bus (USB)port 882 provides connectivity between the printed circuit board 850 anda computer user interface (not shown). An entry point 886 allows forentry of optical and power cables in the unit and a furcation mount 890provides a mechanical mounting bracket for optical and/or power cablefurcation. A power connector 894 connects the cable electrical conductorto the printed circuit board 850.

According to the above embodiments, a variety of wireless services maybe provided to a coverage area. Optical signals are used to transmitdata to the RAUs 650, which allows the RAUs 650 to operate using arelatively low voltage source. A low operating voltage of 48V or less,for example, avoids many of the more onerous requirements of theNational Electrical Code. The optical fiber-based wireless system 600provides the advantage of modularity in that the RAUs 650 can beselected to have a number of differing functionalities, with the HEUs610 also being capable of multiple functionalities, such as varyingoperating bands. The exemplary optical fiber-based wireless system 600is described as supporting three bands to support a variety of servicesfor the coverage area of the optical fiber-based wireless system 600.The optical fiber-based wireless system 600 can be adapted, however, tosupport additional frequency bands. The RAUs 650 can be placedselectively in the coverage area to ensure a good signal at eachsubscriber location. After the passive cabling has been deployed, clientdevices can be added at any time. Frequency bands can also be added orchanged after initial deployment to support capacities such as 3G,cellular, WIMAX, LTE, retail, healthcare applications, RFID tracking,WiFi, and other capabilities.

An optical fiber-based wireless system 600 as illustrated in FIGS.11A-22 is capable of operating in one or more of the following bands(MHz) on downlink in this embodiment: 869-894 (US Cellular), 1930-1990(US PCS), 2110-2155 (US AWS), 925-960 (GSM 900), 1805-1880 (GSM 1800),and 2110-2170 (GSM 2100). The optical fiber-based wireless system 600 iscapable of operating in one or more of the following bands (MHz) onuplink in this embodiment: 824-849 (US Cellular), 1850-1910 (US PCS),1710-1755 (US AWS), 880-915 (GSM 900), 1710-1785 (GSM 1800), 1920-1908(GSM 2100). Input power to the HEU 610 is between 110-220 VAC, 350 W inthis embodiment. The input power to the RAUs 650 is about 48 VDC in thisembodiment.

To provide flexibility in installing, operating, and maintaining anoptical fiber-based wireless system, microprocessors that executesoftware of firmware (referred to collectively herein as “software”) canbe employed in such systems and their components to provide certainfunctionalities. Such optical fiber-based wireless systems can includethe optical fiber-based wireless system 100, 200, 400, and 600previously described. Software provides flexibility in system operationand communication between various components of an optical fiber-basedwireless system for a variety of purposes and functionality, as will bedescribed in more detail below.

For example, as illustrated in FIG. 23, another exemplary opticalfiber-based wireless system 900 is illustrated. A head-end unit (HEU)902 is provided that includes software executing on one or moremicroprocessors or microcontrollers. As will be described in more detailbelow, the microprocessor/microcontroller included in the HEU 902 is adistinct system from the RF components in the HEU 902. Thus, themicroprocessor/microcontroller included in the HEU 902 can operate evenif the RF components are not operational, and vice versa. This allowsthe microprocessor/microcontroller included in the HEU 902 to operate toperform various functions, including monitoring and generating alarmsand logs, as will be discussed in more detail below, withoutinterrupting the RF signals communicated in the optical fiber-basedwireless system. This provides an advantage of being able to power-down,reboot, troubleshoot, and/or load or reload software into the HEU 902without interrupting RF communications. Further, because themicroprocessor/microcontroller included in the HEU 902 is distinct fromRF communications, swapping in and out RF-based modules is possiblewithout interrupting or requiring the microprocessor/microcontrollerincluded in the HEU 902 to be disabled or powered-down. Themicroprocessor/microcontroller included in the HEU 902 can continue toperform operations for other RF-based modules that have not been removedwhile other RF-based module(s) can be removed and replaced.

The HEU 902 also includes downlink and uplink BICs 903 that receive andtransmit RF carrier signals, respectively, to and from one or more RAUs(RAUs) 906 via optical fiber links, as previously discussed. Thedownlink and uplink BICs (not shown) in the HEU 902 also contain one ormore microprocessors or microcontrollers that execute software forperformance in this embodiment, as will be described in more detailbelow. The RAUs 906 are interfaced to the HEU 902 via OIMs 910 aspreviously discussed to transport Radio-over-Fiber (RoF) communicationsignals (or “optical RF signals”) between the BICs 903 and the RAUs 906over the optical fiber links 904, as previously discussed. The OIMs 910in this embodiment also contain one or more microprocessors executingsoftware, as will be described in more detail below. The RAUs 906include optical-to-electrical converters (not shown) to convert receivedRoF signals from the OIMs 910 into RF signals that are radiated viaantennas 905 connected to the RAUs 906. The RAUs 906 also each containone or more microprocessors that execute software, as will be describedin more detail below. More detail regarding the components of theoptical fiber-based wireless system 900 and their operability isdiscussed in more detail below with regard to FIGS. 25-54.

With continuing reference to FIG. 23, by providing microprocessors ormicrocontrollers executing software in the components of the opticalfiber-based wireless system 900, and more particularly the HEU 902,software-based interfaces to the optical fiber-based wireless system 900can be provided. Interfacing to the optical fiber-based wireless system900 can allow flexibility in configuring and monitoring the opticalfiber-based wireless system 900, as will be described by example in moredetail below. For example, the HEU 902 in FIG. 23 can be configured toprovide a direct connection interface 907 to a local client 908 via alocal access port 909, which may be a serial port for example. The localaccess port 909 may be communicatively coupled to components in the HEU902 via a midplane interface card provided in a chassis 911 housing theHEU 902, as an example. The local client 908 may be a human interfacethat is provided by a computer or terminal as an example. The directconnection interface 907 may be provided according to any type ofphysical connector (e.g., USB) and protocol desired (e.g., RS-232).

As also illustrated in FIGS. 23 and 24, the HEU 902 can also beconfigured to interface over one or more networks 912 to provide remoteaccess to functionalities configured to be provided by the opticalfiber-based wireless system 900 over the network 912, including the HEU902 and its components and the RAUs 906. Network interfaces alsofacilitate remote access to the optical fiber-based wireless system 900.Remote access and functionalities may include the ability to configure,monitor status, receive and view alarms and event logs, and updatesoftware for the optical fiber-based wireless system 900 and itscomponents, as will be described in more detail below. These variousfunctionalities and remote access are included in communicationoperations that can be performed by the HEU 902. One or more networkinterface cards or boards 914 may be provided in the chassis 911 of theHEU 902 to communicatively couple components of the optical fiber-basedwireless system 900 to the network 912. As examples, the network 912 mayinclude an Ethernet physical connection. The HEU 902 may include anEthernet board to facilitate connection to the network 912 and to otherHEUs 902, as will be described in more detail below.

As illustrated in FIG. 24, the HEU 902 may include an interface layer918 that handles communication responses and requests regarding theoptical fiber-based wireless system 900 and its components and services919 that will be described in further detail below, to and from clients920 over the network 914. Clients 920 may include deployment clients 922that access the optical fiber-based wireless system 900 duringdeployment and operational clients 924 that access the opticalfiber-based wireless system 900 during operation. The clients 920 may behuman clients or other systems. Examples of deployment clients 922include administrators 926, users 928, and wireless operators 930.Examples of operational clients 924 include engineers 932, monitoringoperators 934, and network management systems 936.

The communication services provided by the interface layer 918 to theclients 920 may be provided according to any communication interface andprotocol desired. As illustrated in FIG. 24, examples include a commandline interface module 938, a hypertext transfer protocol (HTTP)interface module 940, and/or a Machine Interface (MI) protocol interfacemodule 942 may be provided in the interface layer 918 to providesimultaneous client interfacing for clients 920 the optical fiber-basedwireless system 900. The interface modules 938, 940, 942 may be designedso that software specific to the optical fiber-based wireless system 900may not be required to be installed on the clients 920. In thisembodiment, the command line interface module 938 facilitatesinterfacing with a serial emulator client using any terminal emulationsoftware installed on a client 920 (e.g., Telnet, HyperTerm, etc.) Thecommand line interface module 938 allows a client 920 to configure theHEU 902, including the ability to configure either a static or dynamicinternet protocol (IP) address for network communications.

The HTTP interface module 940 facilitates interfacing with web browserclients executing a web browser (e.g., Internet Explorer®, Firefox®,Chrome®, and Safari® browsers, etc.). The MI interface module 942facilitates interfacing with an MI client through an MI protocol. Anexample of an MI protocol is Simple Network Management Protocol (SNMP).In this example, the MI protocol interface 942 could be an SNMP agent.Certain features may be exclusively accessible through certain interfacemodules 938, 940, 942. More detail regarding the interface layer 918 andaccessing of the optical fiber-based wireless system 900 via theinterface layer 918 and the services 919 provided by the opticalfiber-based wireless system 900, including through the interface layer918, are described in more detail below.

Before discussing the various features and functions provided by theoptical fiber-based wireless system 900 and the HEU 902 in thisembodiment via software-based applications executing on microprocessors,an exemplary hardware and software deployment diagram of the opticalfiber-based wireless system 900 and external components is firstdiscussed. In this regard, FIG. 25A is a schematic diagram illustratingan exemplary microprocessor and software deployment diagram of theoptical fiber-based wireless system 900 and external components that caninterface to the optical fiber-based wireless system 900. Moreparticularly, the diagram in FIG. 25A illustrates the variousmicroprocessors or microcontrollers provided in the HEU 902, includingthe BICs 903, the OIMs 910, and the RAUs 906 to facilitate a discussionof the microprocessor and software-based features and controls of theoptical fiber-based wireless system 900. As illustrated in FIG. 25A andpreviously discussed, RF-based modules that include a downlink BIC 949and an uplink BIC 950 are coupled to the OIMs 910 via RF links 951, 952to send and receive RF electrical signals to the OIMs 910, which arecommunicated as RoF signals over RoF links 953 to and from the RAUs 906.The downlink BIC 949 and the uplink BIC 950 are coupled via RF links954, 955, respectively, to a BTS 956 to receive and provide RF carriersignals. In this embodiment, up to twelve (12) OIMs 910 can be providedin the HEU 902 and interfaced to the downlink BIC 949 and uplink BIC950.

As illustrated in FIG. 25A, the HEU 902 in this embodiment includes asingle board HEU controller 958. The HEU controller 958 includes an HEUmicroprocessor 960 in this embodiment that executes an operating systemand application software to perform various features and functions, aswill be described in more detail below. These various features andfunctions are provided by the HEU controller 958 carrying outcommunication operations as will be described in more detail below. Inthis embodiment, the HEU controller 958 can be provided as a generalpurpose commercially available computer board or a customer designcomputer board and may be provided on a single PCB. One example of acommercially available computer board that may be employed ismanufactured by EmbeddedPlanet. The HEU microprocessor 960 can be the440EP™ microprocessor in this embodiment. The HEU microprocessor 960 isconfigured to and executes the Linux® operating system in thisembodiment; however, any other operating system desired could beemployed. The application software and operating system reside in memoryor datastore 966 (e.g., Flash, EEPROM, RAM, etc.) provided as part ofthe HEU controller 958. The application software provided in thisembodiment is specific to the optical fiber-based wireless system 900.

The HEU controller 958 includes several software components or modulesthat provide the features and functionality of the HEU 902 and opticalfiber-based wireless system 900, as will be described in more detailbelow. As illustrated in FIG. 25A, the HEU controller 958 includes a HEUcontroller software module 964 that provides the application softwarethat controls the overall process and features and functions carried outby the HEU microprocessor 960 in the HEU controller 958 for the HEU 902.The HEU microprocessor 960 executes the HEU controller software module964 along with other processes in a multi-threaded system. The HEUcontroller software module 964 is stored in datastore 966 and retrievedby the HEU microprocessor 960 during execution as one process. In thisembodiment, the HEU controller software module 964 is configured to callupon a common module (COMMON INCLUDE) 968 that contains a library ofsoftware functions used to assist carrying out various features andfunctions of the HEU controller software module 964. For example, thecommon module 968 may contain a dynamically linked library (DLL) ofsoftware functions. The common module 968 can include software functionsthat interface with the different hardware components in the HEU 902 viaI²C communications in this embodiment.

The HEU controller 958 in this embodiment also includes a communicationsmodule (COMMS) 970 that contains the communications layer for the HEUcontroller software module 964. The HEU controller software module 964initiates the communications module 970 to communicate with the othermodules and components of the HEU 902, including the downlink and uplinkBICs 949, 950 and the OIMs 910, to carry out features andfunctionalities in the optical fiber-based wireless system 900. Duringinitialization, the software in the communications module 970dynamically links HEU controller software module 964. In this manner,the communications layer provided in the communications module 970 isabstracted from the HEU controller software module 964 to provideflexibility for updating or altering the communications layers in theHEU 902 without requiring updating of the HEU controller software module964.

In this embodiment, the communications module 970 communicates to thedownlink and uplink BICs 949, 950 and the OIMs 910 via addressablemessages communicated over an I²C communication bus 972, as illustratedin FIG. 25A. The I²C communication bus 972 may have a designed busspeed, such as 100 kHz as a non-limiting example. In this manner, thedownlink and uplink BICs 949, 950 and the OIMs 910 are individuallyaddressable in the HEU 902 over the I²C communication bus 972. Othertypes of communication buses could be employed. The communications tothe downlink and uplink BICs 949, 950 and the OIMs 910 are independentof the RF communications involving these modules. Thus, RFcommunications are not interrupted if the communications module 970, theHEU controller 958, or other software or processes executed by the HEUcontroller 958 are not operational. This provides an advantage of the RFcommunications not being dependent on the operation of the HEUcontroller 958 in case of failure. Further, this allows the HEUcontroller 958 or its software to be upgraded, rebooted, powered down,replaced, repaired, etc. without interrupting RF communications in thesystem 900. This may also be advantageous if Quality of Service (QoS)requirements are stringent.

The downlink and uplink BICs 949, 950 each have their ownmicroprocessors or microcontrollers 965, 967 that execute softwarestored in their respective datastore 969, 971, respectively, to processthe I²C messages from the communications module 970, and to provideresponses over the I²C communication bus 972 to the communicationsmodule 970 to be passed on to the HEU controller software module 964 andadditionally to control board functions. The microprocessors 965, 967communicate with components in their respective downlink and uplink BICs949, 950 to provide services requested by the HEU controller softwaremodule 964. The OIMs 910 also each have their own microprocessor 973that executes software stored in datastore 975 to process the I²Cmessages from the communications module 970. The microprocessor 973messages to microprocessors 977 in the RAUs 906 over direct links 979 toconfigure RAUs 906 and to provide other functionalities initiated by theHEU controller 958 and the HEU controller software module 964, as willbe described in more detail below. As illustrated in FIG. 26 anddiscussed below, I²C communications are not employed between the OIMs910 and the RAUs 906 in this embodiment, because the RAUs 906 connectdirectly via serial communications to UART chips on the OIMs 910. Asillustrated in FIG. 25A, up to twelve (12) OIMs 910 can be provided inthe HEU 902 and interfaced to the HEU controller 958 in this embodiment.

The HEU controller 958 in this embodiment also includes an interfacemanager module (INTERFACE MANAGER) 974 that controls the interfacebetween the HEU controller software module 964 and the interface modules940, 942. In this embodiment, the interface module 940 is a web server,and the interface module 942 is an SNMP agent. When the HEU controllersoftware module 964 communicates to the interface modules 940, 942, theHEU controller software module 964 calls upon the interface managermodule 974 which in turn calls upon the appropriate interface modules940, 942 for external communications to clients 920 (FIG. 24).Similarly, communication requests received by the clients 920 for theHEU 902 are communicated from the interface modules 940, 942 to the HEUcontroller software module 964 for processing via the interface managermodule 974. In this manner, the interface manager module 974 isabstracted from the HEU controller software module 964 to provideflexibility for updating or altering the interface layers 918 or addingnew interface modules and protocol capabilities to the HEU 902 withoutrequiring updating of the HEU controller software module 964. The HEUcontroller 958, the interface manager module 974 and the interfacemodules 940, 942 are each separate processes executed by the HEUmicroprocessor 960. The HEU controller 958, the interface manager module974, and the interface modules 940, 942 communicate to each other viainter process communications (IPC).

Visual indicators, such as light emitting diodes (LEDs) for example, maybe included in the HEU 902 and its various components and the RAU 906 tovisually indicate the status of such components to a technician or otherpersonnel when on-site at the HEU 902 and/or RAUs 906. In this manner,general status information can be determined without having to log in tothe HEU 902, unless desired. In this regard, FIG. 25B illustrates atable of the HEU 902 and RAU 906 modules with labels 959 on each module.The labels 959 represent a single visual indicator, which in thisembodiment is an LED. The module controls its visual indicators toindicate status visually. The status of the module is indicated bycontrolling the visual indicator on the module as either “Off” 961,“Green” 963, “Yellow” 981, or “Red” 983 state in this embodiment. Themeaning of each state is noted in the table in FIG. 25B.

In this embodiment, the HEU controller 958 is a distinct system from theRF modules (i.e., downlink BIC 949, uplink BIC 950, OIMs, 910, and RAUs906) and their components. Thus, the HEU controller 958 can operate evenif the RF modules and their components are not operational, and viceversa. This allows the HEU controller 958 to operate to perform variousfunctions, including without limitation monitoring and generating alarmsand logs, and other tasks as will be described in greater detail below,for RF components without interrupting the RF signals communicated inthe RF modules. These various functions are provided by the HEUcontroller 958 carrying out communication operations with modules in thesystem 900 including the downlink BIC 949, the uplink BIC 950, the OIMs910, and/or the RAUs 906. This provides an advantage of being able topower-down, reboot, troubleshoot, and/or load or reload software intothe HEU controller 958 without interrupting RF communications in the HEU902 or RAUs 906. Further, because the HEU controller 958 can be distinctfrom RF communications, swapping in and out the modules in the HEU 902and RAU 906 is possible without interrupting or requiring the HEUcontroller 958 to be disabled or powered-down. The HEU controller 958can continue to perform operations for other RF modules that have notbeen removed while other RF-based module(s) can be removed and replaced.

FIG. 26 illustrates more detail regarding the RF link communicationspecification between the HEU 902 and the downlink BIC 949, the uplinkBIC 950, and the OIMs 910 coupled to the OIM 910 in this embodiment. Thedownlink BIC 949 and the uplink BIC 950 each have their own absolute I²Caddresses (e.g., address 1 and 2). As illustrated therein, there aretwelve (12) slots 980, 982 provided in each of the downlink and uplinkBICs 949, 950 in this embodiment. Up to twelve (12) OIMs 910 can becoupled to the downlink and uplink BICs 949, 950 in the HEU 902 via theslots 980, 982 to provide hardware addressing between the downlink anduplink BICs 949, 950 and the OIMs 910 The downlink BIC 949 carries an RFsignal from the BTS 956 (FIG. 25A) to the OIMs 910 destined for aparticular RAU 906. Similarly, the uplink BIC 950 carries signals fromthe RAUs 906, via the OIMs 910, to the BTS 956. The OIMs 910 also eachhave individual I²C addresses that each allow communicationsindividually to RAU 906 coupled to the OIMs 910. As illustrated in FIG.26, one OIM 910 (which is an OIC in this embodiment) is illustrated asconnected to slot number three (3) on the downlink and uplink BICs 949,950 via a midplane interface card; thus, the hardware address of theillustrated OIM 910 is slot number 3. Providing an communication messageto slot number 3 provides communications from the downlink and uplinkBICs 949, 950 connected to slot 3 with the OIMs 910 coupled to slot 3 asillustrated in FIG. 26.

An example of a hardware address format 984 is provided in FIG. 27. Asillustrated therein, the hardware address format 984 in this embodimentis comprised of ten (10) bits. Five (5) bits are provided to accommodatea slot number 986, and four (4) bits are provided to accommodate an I²Cnumber 988. Each OIM 910 can accommodate up to three (3) I²C addresses991 in this embodiment, as illustrated in FIG. 26, to accommodate up tothree (3) individually addressable RAUs 906 in this embodiment. Each RAU906 is connected directly to the OIM 910 and thus I²C communications arenot used for communications between the OIMs 910 and the RAUs 906. Thus,to address a particular RAU 906, the slot number of the OIM 910 coupledto the RAU 906 to be addressed is provided in the slot number 986followed by the I²C number 988 of the RAU 906. Thus, in this embodiment,the hardware address format 984 can accommodate up to thirty-two (32)slot numbers on the downlink and uplink BICS 949, 950, if provided, andup to sixteen (16) I²C addresses per OIM 910 for a maximum offorty-eight (48) RAUs 906 per OIM 910.

FIG. 28A illustrates an exemplary I²C point address 990, which includesthe I²C address 984 with an RAU 906 number 992 and a pointidentification (ID) 991 for I²C communications between the HEU 902 andmodules to communicate point information. Thus, the I²C address 984 isthe destination for the I²C communication message. The point ID 991represents a type of point regarding a component of the opticalfiber-based wireless system 900. Point information or a point valueregarding the point follows the point I²C address 991 in an I²Ccommunication message. Point IDs are defined during the design of theoptical fiber-based wireless system 900 and are built into the softwarearchitecture of the optical fiber-based wireless system 900 so thatinformation regarding modules (i.e., OIMs 910 and RAUs 906) can bemonitored by the HEU controller 958. The points IDs 991 can be static ordynamic points. Static points are used to provide static informationregarding a component that does not change. Dynamic points are used toprovide dynamic information that can change to provide a current statusor information regarding a component. Points can also be alarmable ornon-alarmable as will be discussed in more detail below.

Clients 920 accessing the optical fiber-based wireless system 900 may beinterested in points for a variety of reasons. For example, bymonitoring a point, a check on status and health of a component in theoptical fiber-based wireless system 900 can be performed. The points canbe monitored and used to calculate alarms (e.g., if a particularhardware component is operating outside a tolerable range). Points canalso be used to provide information or point values to clients 920 andused to calculate and/or generate alarms. Multiple points can beassociated with the different hardware boards in the optical fiber-basedwireless system 900 (i.e., HEU 902, downlink BIC 949, uplink BIC 950,OIMs 910, and RAUs 906). The point values monitored can also be used todetermine aging of the modules. For example, the degradation ofperformance can be tracked over time by tracking the performanceindicators communicated in points from the modules to the HEU 902.

Different microprocessors for different components of the HEU 902 andoptical fiber-based wireless system 900, as previously described andillustrated in FIG. 25A, are capable of providing a point address 990and point information in an I²C communication message. The point format992 is provided as part of a header to the I²C communication message toallow information regarding components and their status to becommunicated to the different software modules in the HEU 902 and inparticular to the HEU controller software module 964. The HEU controllersoftware module 964 will provide certain functionalities to clients 920based on the point ID 994, as will be described in more detail below.

FIG. 28B illustrates an exemplary points list 993 that may used to storepoints 994 based on hardware details. The points 994 may be associatedwith point address that contain point IDs 991 to be identified with theHEU controller 958. Four (4) points are shown in the points list 993,one for each board type 995 (i.e., RAU, DL BIC, UL BIC, and OIM).However, this point list 993 is only a partial list in this embodiment.A plurality of points may be provided for each board type 995. A devicetype 996 where the point 994 is located can be provided in the pointslist 993, which the points 994 example illustrated in FIG. 28B is amicroprocessor. The point 994 may map to hardware information 996,including a hardware signal name 996A, a pin name 996B and pin number996C of the device, a hardware characteristics 996D of the pin (e.g.,input, output), and a hardware description 996E among other information.FIG. 28C illustrates the points list 993 in FIG. 28C as a points list999 accessible at the communications module 970 (FIG. 25A) level. Asillustrated therein, the points have a code variable name 998A for thesoftware as well as a point abbreviation name 998B. The pointabbreviation name 998B is used to provide the point information toclients 920.

The point abbreviation name 998B may follow a standard configuration.For example, the first letter in the point abbreviate name 998B may bethe board type (e.g., “R”=RAU; “D”=downlink BIC; “U”=uplink BIC; and“O”=OIM). The second and third letters in the point abbreviation name998B may be the direction of the point (e.g., “IN”=input; “OU”=output;“MO”=module; “Bx”=band number, “Ox”=oscillator number, etc.). The fourthletters in the point abbreviation name 998B may be the component type(e.g., “A”=amplifier; “N”=attenuator; “O” is oscillator, “S”=switch,etc.). The fifth and sixth letters in the point abbreviation name 998Bmay be the component characteristic (e.g., “L”=level; “S”=status;“E”=enable/disable, etc.) and its instance identification.

As discussed above, points are defined by the optical fiber-basedwireless system 900. More particularly, the component of the opticalfiber-based wireless system 900 responsible for providing particularpoints is also responsible for providing characteristic informationregarding the points to the HEU controller 958, and more particularly tothe HEU controller software module 964 when the component is enumeratedor initialized. In this manner, each component in the opticalfiber-based wireless system 900 can provide information on the meaningof points under its responsibility and how such points should be handledor treated by the HEU controller software module 964 for flexibility.The enumeration process for components of the optical fiber-basedwireless system 900 will be described in more detail below.

As illustrated in FIG. 29, characteristics regarding each point areprovided by flagbits 999 in this embodiment. The flagbits 999 areprovided for each point on enumeration of a component in the opticalfiber-based wireless system 900 responsible for providing such point.The flagbits 999 are received by the HEU controller software module 964and are used to determine characteristic information represented by bitflags and how received points should be handled, including forcalculating alarms on the points. As illustrated in FIG. 29, thirty-two(32) bits are provided in the flagbits 999 in this embodiment. Bitnumber 31, UL/DL PATH, indicates whether a point is associated with adownlink or uplink path of the optical fiber-based wireless system 900.Bit numbers 30-28 provide three (3) bits to provide a units hi, mid, andlo (UNITS HI, UNITS MID, and UNITS LO) for the point. Bit numbers 27 and26 (TYPE HI and TYPE LO) represent a two-bit value indicating whether apoint value or information provided for the point is in ASCII or 16-bitbinary format (i.e., “00” means binary, “01” means 16 byte ASCII value,“10” means 32 byte ASCII value, and “11” means 64 byte ASCII value). Bitnumber 25 (WRITEABLE) indicates if the point's value is writeable by theHEU 902. Bit number 24 (ALARMABLE) indicates whether the point mayreport alarm bits to be used to provide alarm information, as will bedescribed in more detail below.

With continuing reference to FIG. 29, bit number 23 (MODULE ALARM) canindicate that an alarm point is set by hardware and not calculated bythe HEU 902, if modules can provide alarms to the HEU 902. Bit numbers22 and 21 (ALARM TYPE HI, ALARM TYPE LO) indicate the type of alarmprovided by the point (i.e., “00” means Boolean alarm; “01” means highalarm; “10” means low alarm; and “11” means sticky alarm). The alarmtype may control how the alarm is handled by the HEU 902 and/or theclient 920. Bit number 20 (DYNAMIC) indicates whether the point is astatic or dynamic point. (i.e., “0” means static; and “1” means dynamicin this embodiment). Static points cannot change their point value, butdynamic points can change their point value. Bit numbers 19-14 in thisembodiment provide the initial offset (INIT OFFSET FCN), initialstepsize (INIT SETPSZ FCN), initial hysteresis stepsize (INIT HYSTERFCN), initial threshold (INIT THOLD FCN, initial setpoint (INIT SETPTFCN) and initial value (INIT VALUE FCN). The “FCN” notation indicatesthat the initial values for these bits are defined by a function ratherthan a predefined, fixed value.

Bit numbers 13-12 in this embodiment (UNALLOCATED) are unallocated. Bitnumber 10 (VALUE) indicates whether a point value is present for thepoint followed in an enumeration query. Bit number 9 (NAME) indicatesthat there is an ASCII character name associated with the point. Bitnumber 8 (SETPOINT) indicates that there is a 16-bit setpoint associatedwith the point. Bit number 7 (THRESHOLD) indicates that there is a16-bit threshold value associated with the point. Bit number 6(HYSTERESIS) indicates that there is a 16-bit hysteresis valueassociated with the point. Bit numbers 5 and 4 (MIN THRESHOLD and MAXTHRESHOLD) indicate that there are minimum and maximum threshold valuesassociated with the point. Bit numbers 3 and 2 (MIN HYSTERESIS and MAXHYSTERESIS) indicate that there are minimum and maximum hysteresisvalues associated with the point. Bit number 1 (STEP SIZE) indicatesthat there is a 32-bit floating point step size associated with thepoint. Bit number 0 (OFFSET) indicates that there is a 32-bit floatpoint offset associated with the point.

Against the backdrop of the microprocessor and software architecture andcommunication of the HEU 902 and the HEU controller 958 discussed above,the remainder of this disclosure will discuss the exemplary features andfunctions that can be carried out by the HEU controller 958. In thisregard, FIG. 30 illustrates an exemplary thread diagram 1000 in the HEUcontroller 958 of the HEU 902 of the optical fiber-based wireless systemof FIG. 23. More specifically, the thread diagram 1000 includes threads1002 or software processes executed by the HEU microprocessor 960 in amulti-tasking environment. The threads perform various features andfunctions, some of which involve communicating with components of theHEU 902 and optical fiber-based wireless system 900. FIG. 30 alsoillustrates the inter-thread communication (i.e., request and response)paths between the different threads 1002 and modules to carry outdesigned features and functions of the HEU 902 and the opticalfiber-based wireless system 900. In this embodiment, the communicationsbetween different threads 1002 are carried out by interprocesscommunications (IPC) as previously discussed. Each thread 1002 includesa message queue (not shown) stored in datastore 966 that receivesrequests from other threads 1002. Each thread 1002 reviews its ownrequest queue to process any requests and to then provide responses tothe requesting thread 1002. Further, the datastore 966 can be configuredas shared memory to allow different threads 1002 to access the datastore966 to access or share information.

As illustrated in FIG. 30, six (6) threads 1002 are provided in the HEUcontroller 958 and executed by the HEU microprocessor 960. A HEUcontroller process 1001 is the first process that starts upon start-upor reset of the HEU 902 and HEU controller 958. The HEU controllerprocess 1001 is provided as software that executes at startup or resetfrom the HEU controller software module 964 in this embodiment. The HEUcontroller process 1001 controls the overall process performed by theHEU controller 958. The HEU controller process 1001 starts and controlsfive (5) other threads 1002 at initialization or reset of the HEU 902.In general, one thread 1002 started by the HEU controller process 1001is the logger thread (LOG) 1004. The logger thread 1004 is responsiblefor logging event information for the HEU 902 and the opticalfiber-based wireless system 900 in datastore 966 (FIG. 23). Moreinformation regarding the logger thread 1004 and its functions arediscussed in more detail below. Another thread 1002 initiated by the HEUprocess 1001 that is executed by the HEU microprocessor 960 is thecommunications thread 1006 (COMM). The communications thread 1006provides the communications interface between the HEU controller process1001 and other components of the HEU 902 and RAUs 906 in the opticalfiber-based wireless system 900 as previously discussed. Thecommunications thread 1006 calls upon the communications module 970 tocommunicate with such other components as previously discussed withregard to FIG. 23.

Another thread 1002 initiated by the HEU controller process 1001 that isexecuted by the HEU microprocessor 960 is the scheduler thread 1007(SCHEDULER). Among other features, the scheduler thread 1007 isresponsible for discovering and initializing or enumerating componentsor modules in the HEU 902 and the optical fiber-based wireless system900, generating point list information based on the flagbits 999 (FIG.29), updating module states and point information, and calculating andreporting alarms for modules in the optical fiber-based wireless system900. These features will be discussed in more detail below. Anotherthread 1002 initiated by the HEU controller process 1001 that isexecuted by the HEU microprocessor 960 is the calibration thread(CALIBRATION) 1008. The calibration thread 1008 is responsible forcalibrating the RF links in the optical-fiber wireless based systems900. Another thread 1002 initiated by the HEU controller software module964 that is executed by the HEU microprocessor 960 is the externalinterface thread (EXTERNAL INTERFACE) 1010. The external interfacethread 1010 can be called upon by other threads 1002 to communicate datato external clients 920 and to receive requests from those clients 920.Such requests can include requests to retrieve and view information,calibrate the optical fiber-based wireless system 900 and itscomponents, and other various tasks as will be described in more detailbelow.

A datastore module 1012 is also provided in the HEU controller 958 tostore data in datastore 966 from other threads 1002. The datastore 966can involve different and multiple memory types and include separatepartitions for configurations information, alarm information, and loginformation as will be described in more detail below. The datastoremodule 1012 also facilitates the storage of information, including listsor tables of modules present, their points and point information, andconfiguration information of the HEU 902 and optical fiber-basedwireless system 900, in datastore 966 for retrieval, when needed orrequested. This information may be obtained from the datastore 966 bythe threads 1002 and the clients 920 via the external interface thread1010. The datastore module 1012 can provide one or more registers forwriting and reading data regarding the optical fiber-based wirelesssystem 900 stored in datastore 966. However, the datastore module 1012is not a separate thread in this embodiment. The datastore module 1012is provided as part of the HEU controller software module 964 and itsprocess.

Because the datastore 966 is provided apart and distinct from the RFcommunications in the HEU 902, any information stored in the datastore966, such as configuration information for example, can be retained andpreserved even if RF modules are disabled, interrupted, or otherwise notoperating. When an RF module is disabled and restored for example, afterthe module is discovered, the configuration information stored in thedatastore 966 for such module can be reestablished.

FIG. 31 is a flowchart that illustrates an exemplary process performedby the HEU controller 958 upon startup or reset of the HEU 902. Theprocess is performed by the HEU controller 958 to perform the overallsoftware-based operation of the HEU 902 and to continuously determinethe status of the program and external user requests. The process isprovided as part of the HEU controller process 1001, which is executedby the HEU controller 958 at startup or reset. As illustrated in FIG.31, the process starts via a startup or reset (block 1020). The firststep performed is to initialize and start operations of the HEUcontroller 958 (block 1022). This task initiates the thread startupsequence 1024 illustrated in the exemplary communication diagram of FIG.32 to start the threads 1002 in the HEU controller 958 as previouslydiscussed. As illustrated in FIG. 32, the HEU controller process 1001first reads the configuration of the HEU controller 958 (block 1026) andthen makes a call to the common module 968 (FIG. 25A) to initialize thelogger settings (block 1028) and to start the logger thread 1004 (FIG.30) (block 1030). The logger thread 1004 will then execute its ownlogger thread process to carry out the functions of the logger thread1004 and to handle logger thread requests from the HEU controllerprocess 1001 and the scheduler and communications threads 1007, 1006(see FIG. 30) (block 1032). The logger thread 1004 may be desired to bestarted first so that event logging is activated to be able to storeevent information generated by the other threads 1002.

With continuing reference to FIG. 32, the HEU controller process 1001then makes a call to the communications module 970 (FIG. 25A) toinitialize the communication settings (block 1034) and to start thecommunications thread 1006 (FIG. 30) (block 1036). The communicationsthread 1006 will then execute its own communications thread process tocarry out the functions of the communications thread 1006 and to handlecommunication requests from the HEU controller process 1001 and thescheduler and calibration threads 1007, 1008 (see FIG. 30) (block 1038).The communications thread 1006 is started before the scheduler,calibration, and external interface threads 1007, 1008, 1010 in thisembodiment, because those threads perform functions and features thatmay require or cause communications to components within the HEU 902 andRAUs 906 that require the services of the communications thread 1006.

With continuing reference to FIG. 32, the HEU controller process 1001then makes a call to the common module 968 (FIG. 25A) to create andinitialize the datastore module 1012 to provide datastore for storeevents (blocks 1040, 1042). As previously discussed, the datastoremodule 1012 is not provided in a separate thread or process in thisembodiment. The datastore module 1012 handles data storage from thescheduler, calibration, and external interface threads 1007, 1008, 1010(see FIG. 30) (block 1038).

With continuing reference to FIG. 32, the HEU controller process 1001next makes a call to the HEU controller software module 964 (FIG. 25A)to initialize the scheduler settings (block 1044) and to start thescheduler thread 1007 (FIG. 30) (block 1046). The scheduler thread 1007will then execute to carry out certain functions, including discovery,enumeration, and monitoring functions for modules in the opticalfiber-based wireless system 900 (see FIG. 30) (block 1048).

Lastly, as illustrated in FIG. 32, the HEU controller process 1001 makesa call to the interface manager module 974 (FIG. 25A) to initialize theexternal interface settings (block 1050) and to start the externalinterface thread 1010 (FIG. 30) (block 1052). The external interfacethread 1010 will then execute its own external interface thread processto carry out the functions of the external interface thread 1010 and tohandle communication requests from the HEU controller process 1001 andthe logger and communications threads 1004, 1006 (see FIG. 30) (block1054). After the initialization of the threads 1002 is performed, theHEU controller process 1001 then returns to the main process in FIG. 31.

With reference back to FIG. 31, the HEU controller process 1001 nextperforms some optional steps (blocks 1056-1058, 1066-1086). For example,the HEU controller process 1001 may enter monitoring and registermonitoring timeout information to periodically check status according toa configurable interval of time (block 1056). This is to setup twoprocess handling loops with the main HEU controller process 1001. Thefirst process is to receive and handle requests from the threads 1002that are not involved with user requests. These requests are checkedmore frequently than user requests initiated via the external interfaceprocess 1010. In this regard, as illustrated in FIG. 31, the HEUcontroller process 1001 determines if a timeout has occurred (block1058) such that the HEU controller process 1001 should determine if auser input to restart operation or shutdown the HEU 902 has beenreceived via the external interface process 1010 (block 1060).Alternatively, the HEU controller process 1001 could simply wait foruser input (block 1060) after initializing and starting operations(block 1022). If so, the HEU controller 958 either stops operation if arestart operation request was received (block 1062) and the HEUcontroller 958 is reinitialized (block 1022), or the HEU controller 958is shut down (block 1064) if the user input was a shutdown request. Ifthe user input is not to restart or shutdown the HEU controller 958, theuser input is handled as part of the normal HEU controller process 1001operation, as described below.

The normal HEU controller process 1001 involves checking thecommunications thread 1006 queue length to ensure that anycommunications bottlenecks that occur between inter-threadcommunications to the communications thread 1006 are resolved. The mainfeatures and functions of the HEU controller 958 are performed withinthe other threads 1002, as will be discussed in more detail below. Inthis regard, the HEU controller process 1001 sends a message to thecommunications thread 1006 to get the length of the communicationsthread 1006 get request queue (block 1066). The get request queue is amessage queue provided in datastore 966 that the communications thread1006 reviews to receive communications requests from the schedulerthread 1007 (see FIG. 30). If the length of the get request queue islonger than a given threshold limit (block 1068), the get requestthreshold provided in the scheduler thread 1007 is lowered (block 1070).This is because the scheduler thread 1007 may be responsible forproviding a request rate to the communications thread 1006 that exceedsa desired threshold limit for the get request queue, thus providing alatency issue in the HEU controller 958.

Thereafter, the HEU controller process 1001 sends a message to thecommunications thread 1006 to obtain the length of the set request queue(block 1072). The set request queue is the message queue provided indatastore 966 that the communications thread 1006 reviews to receivecommunications requests from the external interface thread 1010. If thelength of the set request queue is longer than a given threshold limit(block 1074), the set request threshold provided in the externalinterface thread 1010 is lowered (block 1076). This is because theexternal interface thread 1010 may be responsible for providing arequest rate to the communications thread 1006 that exceeds a desiredthreshold limit for the set request queue, thus providing a latencyissue.

Next, with continuing reference to FIG. 31, the HEU controller process1001 checks for any reported errors by the other threads 1002 (block1078) and determines if such errors are of a high severity thatoperation of the HEU controller 958 should be stopped (block 1080). Forexample, the HEU controller 958 may determine if there has been a reseton the HEU 902 or a watchdog error has occurred (e.g., timer expiredthat is not reset by the software) to determine if the softwareexecuting in the HEU controller 958 has incurred an error or exceptionsuch that a restart is required. Events are generated by alarms that areeither reported or calculated by other threads 1002 of the HEUcontroller 958 as will be discussed in more detail below. The events arestored in datastore 966 as part of the logger thread 1004. In thisembodiment, high severity or critical alarms may be stored in anon-volatile memory partition, and non-critical alarms may be in aseparate partition as part of the datastore 966. System events,discussed in more detail below, may be stored in either non-volatile orvolatile memory in a separate partition in the datastore 966. If theevent is not of high severity, the process loops back to the checktimeout task (block 1058) to repeat the process in a continually loopingfashion. If the event is of high severity, the HEU controller process1001 stops operation of the HEU controller 958 (block 1082) and waitsfor user input (block 1084). The user input can either be to shut downthe HEU controller 958 or to restart the HEU controller 958 (block1086). If the unit input is to shutdown, the HEU controller 958 executesa shutdown operation to terminate the threads 1002 and their messagequeues in a design manner (block 1064). If the user input is to restart,the HEU controller 958 executes a restart operation by returning back tothe initialization of the threads 1002 (block 1022), previouslydiscussed above.

FIGS. 33A and 33B are a flowchart illustrating the process performed bythe scheduler thread 1007 illustrated in FIG. 30. As will be discussedin more detail below, the scheduler thread 1007 is responsible fordiscovery and initialization of modules. Modules include components inthe HEU 902 (DL-BIC 949, UL-BIC 950, and OIM 910) and the RAUs 906. Forexample, each component may be provided on a physical PCB. Modules areinitialized by the HEU controller 958 before they are operational. Thescheduler thread 1007 also generates a point list for components in theHEU 902 and the RAU 906 according to the flagbits 999 provided for eachpoint type configured in datastore 966 of the HEU controller 958, aspreviously discussed and illustrated in FIG. 29. The scheduler thread1007 sends messages to the communications thread 1006 to carry out thesefeatures. Further, the scheduler thread 1007 is responsible for updatingthe state of modules, updating dynamic points, calculating alarms, andreporting point alarms in the datastore 966, which may be assessed byclients 920 via the external interface process 1010.

With reference to FIG. 33A, the scheduler thread 1007 starts byreceiving an initialization event (block 1100) from the HEU controllerprocess 1001 (block 1102). The scheduler thread 1007 operates on a timeinterval. In this regard, the scheduler thread 1007 next determines ifit is time to perform one of four requests sent to the communicationsthread 1006 in a request stage 1104 (block 1106). Only one of the fourtypes of requests is performed on each iteration of the scheduler thread1007. However, each type of request need not necessarily be executedwith the same frequency. Each type of request may be performed atdifferent periodic intervals depending on the desired timing resolutionof the four types of communications thread 1006 requests. The desiredtiming intervals can be configured by a client 920 in a configurationprocess, which will be described in more detail below. After the requeststage 1104 is performed by performing one of the four types ofcommunication requests, the scheduler thread 1007 executes a responsestage 1108. The response stage 1108 involves reviewing a schedulermessage queue for messages sent to the scheduler thread 1007 by otherthreads 1002 and performing the request. The response stage 1108 isperformed in each iteration of the scheduler thread 1007. As will bedescribed in more detail below, the scheduler thread 1007 is responsiblefor discovering modules, updating module statuses, updating pointsinformation, and calculating and reporting alarms; thus, the otherthreads 1002 send requests to the scheduler queue to perform these taskswhen needed or desired.

With continuing reference to FIG. 33A, a first type of request in therequest stage 1104 is a discovery request (block 1110) for modules sentto the communications thread 1006. The discovery request may beperformed automatically and periodically, for instance, every fifteen(15) seconds as an example. Thus, as modules are removed and replaced,the replaced modules are automatically discovered. Thus, hot swapping ofmodules is possible while the HEU controller 958 is operational. Thediscovery requests involve communicating discovery requestsasynchronously to I²C addresses in the HEU 902 and the opticalfiber-based wireless system 900 via the communications thread 1006 todiscover the modules present. Modules that are present and have afunctional I²C address are discovered. The modules include the DL-BIC949, UL-BIC 950, OIMs 910, and RAUs 906 in this embodiment. Likewise,the discovery process will also indicate if a previously discoveredmodule has been removed from the HEU 902 or optical fiber-based wirelesssystem 900. The discovery process will result in a response from themodule as well which contains the number and types of points configuredfor the module as the points configured for the module.

Each module contains certain configured points that provide eitherstatic or dynamic information about the module and its components to theHEU controller 958. In this manner, the modules are responsible forreporting their point capabilities to the HEU controller 958 forflexibility. In this embodiment, the first point communicated back tothe schedule thread 1007 indicates the total number of points for themodule that can be requested by the HEU controller 958. After a moduleis discovered, the scheduler thread 1007 places the discovered modulelist of all modules as well as their configured points in datastore 966(FIG. 25A). In this manner, the HEU controller 958, via the threads1002, can communicate with the various modules to provide certainfunctionalities and features described herein. Responses from themodules as a result of the discovery requests are communicated back tothe scheduler thread 1007 queue and processed in the response stage1108.

The module discovery determines the number of OIMs 910 provided in theHEU 902 and in which slots the OIMs 910 are connected to the downlinkand uplink BICs 949, 950. In this embodiment, up to two hundredfifty-six (256) modules can be discovered by the HEU controller 958,however, such is not a limitation. Further, module discovery alsodetermines the RAUs 906 connected to each OIM 910 via communicationsfrom the communications thread 1006 to the OIM 910. As previouslydiscussed, the RAUs 906 are not directly addressable on the I²Ccommunication bus 972, but each RAU 906 has a unique I²C address foraccess via the OIMs 910 (FIG. 25A). After a module is discovered by thescheduler thread 1007, the module state is changed from an uninitializedstate (MODULE_UNINITIALIZED) 1114 to a discovered state(MODULE_DISCOVERED) 1116, as illustrated in the module state diagram ofFIG. 34. The module state diagram in FIG. 34 illustrates a state diagramthat is executed in the modules by their respective microprocessors inresponse to module requests from the scheduler thread 1007 via thecommunications thread 1006. The module executes a discovery handshakecommunication 1118 with the communications thread 1006 and transitionsto the discovered state 1116 if no error occurs. If the module receivesother communications messages while in the uninitialized state 1114, themodule will reject such other messages 1120 until the module isdiscovered, as illustrated in FIG. 34.

FIG. 35 illustrates an exemplary communications sequence 1121 to thecommunications thread 1006 to further illustrate communications to thecommunications thread 1006. As illustrated therein, the communicationsthread 1006 makes a call (block 1123) to a request queue 1125 todetermine if a request has been communicated to the communicationsthread 1006. The request is related to a particular module. Thecommunications thread 1006 checks to determine if the module statematches the request (block 1127). For example, as illustrated in FIG.34, a module in the uninitialized state 1114 cannot receive messagesother than discovery requests from the scheduler thread 1007. If amismatch is present between the module state and the request, thecommunications thread 1006 makes a call to report the mismatch (block1129) and adds the mismatch to the requester's queue 1131 (block 1133).If there is not a mismatch, the communications thread 1006 sends therequest message to the microprocessors 960, 973 of the module (FIG. 25A)(block 1135), which in turn sends the message (block 1137) to the I²Caddress of a module 1139. The module microprocessors 960, 973communicate a response back to the communications thread 1006 (block1141). The communications thread 1006 can then check the module responsefor errors (block 1143).

Turning back to FIG. 33A, another type of request performed by thescheduler thread 1007 in the request stage 1104 is the enumerate modulerequest 1122. Enumeration is the process of requesting and receivingpoint information for the points from the discovered modules. The pointinformation will be used to provide status of module and certain of itscomponents as well as to receive and calculate alarms, as will bediscussed in more detail below. For modules that are discovered and in adiscovered state (block 1124), the scheduler thread 1007 generates anenumeration points request (block 1126) and sends the enumeration pointsrequest to the discovered module via the communications thread 1006(block 1128). The HEU controller 958 does not already need to be awareof the points that can be provided by the module. If the points changefor a particular module, upon enumeration of the module, the pointinformation for such module will be updated in the HEU controller 958 bythe scheduler thread 1007 automatically.

The scheduler thread 1007 generates the enumerating points request(block 1126) and sends the enumerating points request for a discoveredmodule to the communications thread 1006 destined for the module via I²Ccommunications (block 1128). The module receives the enumerating pointsrequest 1122 from the communications thread 1006 while in the modulediscovered state 1116, as illustrated in FIG. 34. In response, themodule will enumerate the points configured for the module. Thisincludes receiving the flagbits 999 configured for each point to providethe HEU controller 958 with the characteristic information for thepoints for the module. The point information received from a module bythe scheduler thread 1007 will be updated in the points informationstored in the datastore 966 for access by the HEU controller 968.Because the scheduler thread 1007 receives the points for eachdiscovered module, the scheduler thread 1007 can track whetherenumeration is complete by determining if all point information has beenreceived for each discovered module in the request stage 1104. Afterenumeration is completed 1132, the module transitions to the moduleinitialized state 1134. In the initialized state 1134, the module caneither receive requests from the HEU controller 958 to set pointinformation or get point information 1140 to update the pointsinformation stored in datastore 966 of the HEU controller 958. As willbe discussed below, the points information may be used to calculate orreport alarms and may be accessed by clients 920 via the externalinterface thread 1010.

As also illustrated in FIG. 34, an initialized module remains in theinitialized state 1134 until a reset 1136 or timeout 1138 occurs, bothof which place the module back in the uninitialized state 1114 until thescheduler thread 1007 discovers the module. In this manner, the opticalfiber-based wireless system 900 supports removing and replacing (alsocalled swapping in and out) OIMs 910 from the HEU 906 and RAU 906connections to the OIMs 910 during operation or when “hot” to provide“hot swapping.” If an OIM 910 is removed, a failure to receive anacknowledgement will be detected by the HEU controller 958 via thescheduler thread 1007 when the module is attempted to be re-discoveredby the HEU controller 958 thus removing the module from the list ofdiscovered modules in the datastore 966. When the module is inserted orreinserted, or communications otherwise reestablished with the HEUcontroller 968, the scheduler thread 1007 will be able to discover,enumerate the points, and initialize the module automatically. Hotswapping OIMs 910 and RAUs 906 in and out of the optical fiber-basedwireless system 900 will not affect the communications with other OIMs910 and RAUs 906.

In this embodiment, there are four types of alarms that are eithercalculated by the HEU controller 958, and the scheduler thread 1007 inthis embodiment, or by the module that provides the point. Bit number 23in the flagbit 999 settings for each point previously discussed andillustrated in FIG. 29 controls the configuration as to whether an alarmfor a point is calculated by the HEU controller 958 or the module thatprovides the point. The four types of alarms are Boolean, High Alarm,Low Alarm, and Sticky Alarm in this embodiment. Boolean alarms indicatethat either the actual value of the point is the expected value. A HighAlarm indicates that the value for the point exceeded a configuredthreshold value. A Low Alarm indicates that the value for the pointdropped below a configured threshold value. A Sticky Alarm stays set fora point until the point is read, whether or not the value for the pointleaves the threshold range that caused the alarm. The ability to providethreshold values for alarm points allows the HEU 902 to not only detectfailures but to predict failures. The thresholds for alarm points can beset such that exceeding the threshold is indicative of a predicted orpossible future failure as opposed to an actual failure.

This alarm scheme allows any point to be defined as an alarm as neededfor any module. When the points are enumerated by the scheduler thread1007, as discussed above, the HEU controller 958 will know which pointsare alarm from the flagbits 999 and also whether each alarm is to becalculated, either by the HEU controller 958 or the module itself. Thisallows flexibility for any modules to provide its own alarms rather thanrequiring the HEU controller 958 to calculate an alarm. As an example,an example of a module determined alarm may be a point named “RINMVL”which means that RAU 906 input module voltage level. The schedulerthread 1007 will have noticed the alarm module bit (bit number 23) inthe flagbits 999 is set for this point alarm during enumeration of themodule and understand that this alarm point is calculated or set by theRAU 906. When the alarm point is obtained as a dynamic point as part ofthe get alarm point processing by the scheduler thread 1007 discussedbelow, the scheduler thread 1007 will receive the Boolean value of thealarm and report the alarm for posting.

Returning to FIG. 33A, another type of request performed by thescheduler thread 1007 in the request stage 1104 is the get alarm pointsrequest 1142. In this embodiment, providing a separate get alarm pointsrequest 1142 is optional since all points could be handled genericallyin a get points request 1150, discussed in more detail below. Ifprovided as a separate request, the get alarm points request 1142 ispart of a monitoring functionality of the HEU controller 958 to monitorthe status of the points for the modules, including alarms. For modulesthat are in the initialized state (block 1144), the scheduler thread1007 generates the get alarm points request (block 1146) and sends theget alarm points request to the initialized modules via thecommunications thread 1006 (block 1148). The module receives the getalarm points request, via the communications thread 1006, while in theinitialized state 1134 (FIG. 34) and provides the alarmable points forthe module back to the scheduler thread 1007, via the communicationsthread 1006, to be processed in the response stage 1108, as discussedbelow.

Alarmable points are points in which an alarm can be calculated ordetermined by the scheduler thread 1007 according to conditions providedfor the point in the flagbits 999, as previously discussed (FIG. 29).The alarms for certain points are calculated by the scheduler thread1007 and alarms for other points may be determined by the module itself.Points that have alarms calculated by the scheduler thread 1007 areconfigured in this manner to give a user or client 920 the ability toconfigure the alarm thresholds for such points. The ability to configurethresholds can be used to predict failures in the optical fiber-basedwireless system 900. The thresholds for certain points can be set suchthat if exceeded, an actual failure has not occurred, but may beindicative of potential failure that should be noted and reported.Points that have alarms may be calculated by either the module or theHEU controller 958. The information in the alarms may be used to predictfailure or aging of a module based on the information configured for thealarm. For example, the flagbits 999 for a particular point may beconfigured to generate a Low Alarm when performance degrades, but not toa point of failure.

Another type of request performed by the scheduler thread 1007 in therequest stage 1104 is the get points request 1150. For modules that arein the initialized state (block 1152), the scheduler thread 1007generates a point list based on the enumeration response from thediscovered modules (block 1154). The scheduler thread 1007 then sends aget points request to the initialized modules via the communicationsthread 1006 (block 1156). The module receives the get points request,via the communications thread 1006, while in the initialized state 1134(FIG. 34) and provides the points for the module back to the schedulerthread 1007, via the communications thread 1006, to be processed in theresponse stage 1108, as discussed below. The points can be stored in thedatastore 966 for access by the HEU controller 958 and clients 920 viathe interface manager module 974. In this embodiment, clients 920 accessthe points, event information, and other information regarding the HEU902 via the interface manager 966, which retrieves the information fromdatastore 966. In this regard, the datastore 966 is shared memory thatacts as a method of sharing data between different threads 1002 viadirect interfacing to the datastore 966.

After the scheduler thread 1007 performs the request stage 1104, thescheduler thread 1007 performs the response stage 1108. The schedulerthread 1007 checks the scheduler response queue in datastore 966 todetermine if any responses are pending in the queue from other threads1002 (block 1160). Responses can be generated and placed in thescheduler response queue in response to requests in the request stage1104 of the scheduler thread 1007. As continued on FIG. 33B, if thescheduler response queue is empty (block 1162), the scheduler thread1007 checks for pending requests (block 1164). If requests are pending,responses are to be expected to be provided in the scheduler responsequeue. The scheduler response queue should not be empty if there arepending requests. If pending requests are higher than a certainthreshold configured (block 1166), then the scheduler thread 1007 is notprocessing requests fast enough. Thus, the scheduler thread 1007 returnsback to the check response queue task (block 1160) to process responsesprior to performing another request in the request stage 1104.

The scheduler thread 1007 will continue to process responses until theresponse queue is lower than the threshold value (blocks 1166, 1160). Ifthe pending requests were not higher than the threshold value (block1166), the scheduler thread 1007 reports a system error event sincerequests are not being received in response to responses (block 1168).The scheduler thread 1007 then determines if a stop operation requesthas been received (block 1170). If not, the process returns to therequest stage 1104 (block 1106). If a stop operation has been received(block 1170), the scheduler thread 1007 waits for pending requests tocomplete (block 1172) and performs a clean up procedure (block 1174)before exiting the scheduler thread 1007 (block 1176). In this case, thescheduler thread 1007 is no longer active and the scheduler thread 1007must be reinitiated by the HEU controller process 1001 in order to bereactivated.

If the scheduler response queue is not empty (block 1162), this meansthere is a response in the scheduler response queue to be processed. Inthis event, the scheduler thread 1007 determines the response type(block 1178). If the response type is a module communication ordiscovery error, the module state is updated to an uninitialized statein the HEU controller 958 (block 1180) and this information is updatedin the datastore 966 via a call to the datastore module 1012 (block1182). If the response type is a module enumerated response, the moduleis discovered. The scheduler thread 1007 updates the points for thediscovered module to the scheduler thread 1007 via the communicationsthread 1006 (block 1183). The points include the point itself as well ascharacteristics of the point according to the flagbits 999 (FIG. 29), aspreviously discussed. The points are stored in the datastore 966 via acall to the datastore module 1012 so that the scheduler thread 1007 andthe external interface thread 1010 can access the points and storedpoint information received from the modules from the datastore 966(e.g., via get alarm points request 1142 and get points request 1150).

With continuing reference to FIG. 33B, the scheduler thread 1007 is alsoconfigured if the response type is a get points response type (resultingfrom either a get alarm points request 1142 or a get points request1150) the scheduler thread 1007 calculates an alarm for the point (block1186). The module defines whether a point is alarmable in the flagbits999 setting for the point, as previously discussed (FIG. 29). Again,this configuration allows the modules to provide to the HEU controller958 whether a point is alarmable or not. If not alarmable, the schedulerthread 1007 does not calculate an alarm for the point and the pointinformation is stored in datastore 966. If calculated, the alarm for thepoint is updated in datastore 966 (block 1182).

FIG. 36 illustrates a communication or sequency diagram 1200 thatfurther illustrates the calls made by the scheduler thread 1007 toprocess alarm points. As illustrated therein, the scheduler thread 1007checks the response type of the response message in a scheduler responsequeue 1202 (block 1178) (see also FIGS. 33A and 33B). The schedulerthread 1007 then makes a call to a point information list 1204 where theflagbits 999 of the point information are stored when points areenumerated as part of the request stage 1108 in the scheduler thread1007 (block 1206). The point information list 1204 may be provided aspart of an object-oriented class, as an example. If the point isalarmable, the scheduler thread 1007 makes a call on the pointinformation list 1204 to calculate the alarm for the point (block 1208).The alarm is calculated based on the information stored in the flagbits999. The scheduler thread 1007 determines if the desired or configuredcharacteristics provided in the flagbits 999 of the point by the moduleproviding the point (e.g., OIM 910, RAU 906) are within currentoperating conditions. If the alarm state of the point has changed (block1210), the scheduler thread 1007 reports the change to a log file via amessage placed in a logger queue for the logger thread 1004 (block1212), which adds the alarm state to a logger queue 1214 in datastore966 (block 1216). The scheduler thread 1007 also stores the pointinformation in the points list 997 (FIG. 28C) in datastore 966 via acall to the datastore modules 1012 (block 1218). If there is no changein alarm state, the scheduler thread 1007 does not report the alarm tothe logger queue 1214.

With continuing reference to FIG. 36, in response to receipt of thereport in the change of alarm state from the scheduler thread 1007(block 1212), the logger thread 1004 executes a process according to acommunication diagram 1220 also illustrated in FIG. 36. As illustratedtherein, the logger thread 1004 first sends a call to the logger queue1214 to determine if a message has been placed in the logger queue 1214for the logger thread 1004 (block 1222). In the example of a changedalarm state of a point discussed above and illustrated in FIG. 36, amessage to log an alarm for a point will be present in the logger queue1214. If a message is present in the logger queue 1214, the loggerthread 1004 determines the type of message (block 1224) and determinesif logging of point information or the alarming point is enabled (block1226). The logger thread 1004 may also be configurable to iscommunicated externally. If enabled, the point alarm is reported to theHEU controller process 1001 (block 1228) and from the HEU controllerprocess 1001 to the external interface thread 1010 (block 1230) so thatthe point alarm can be reported to clients 920 via a call to theexternal interface thread 1010. Thereafter, the logger thread 1004writes the point alarm to the log file in datastore 966 (block 1232) andreiterates to process the next message in the logger queue 1214, if amessage is present (block 1222).

FIG. 37 illustrates a sequence diagram 1230 of communication requests tothe logger thread 1004 in general that allow threads 1002 to send logrequests to store events for the optical fiber-based wireless system900. Different types of events can be logged using the logger thread1004 in this embodiment. The scheduler thread 1007 and other threads1002 can initiate system events. A first type of system event is anerror message. An error message may be logged whenever an error isdetermined to have occurred by a process carried out by a thread 1002 inthe HEU controller 958. A second type of system event is a threadmessage to provide tracing of communications through threads 1002 fortroubleshooting and debugging purposes. A third type of system event isto log an alarm for a point. This function was previously illustrated inthe FIG. 36 and in the communication diagram 1220 illustrated therein. Afourth type of system event is a trace message that indicates thecurrent activity being performed by the HEU 902.

In this regard, taking the example of the scheduler thread 1007reporting a system event for logging, the scheduler thread 1007 callsupon the common module 968 to log a system event (block 1232). Thecommon module 968 places the log request into the logger queue 1214(block 1234) (see also, FIG. 36). The logger thread 1004 retrieves themessage from the logger queue 1214 (block 1236). The system eventdetails of the log request are communicated to the external interfacethread 1010 via the HEU controller process 1001 so that clients 920 canbe updated with the system event (block 1240). Not every system event iscommunicated to the HEU controller thread 1001 to be communicated toclients 920 via the external interface thread 1010 in this embodiment.This function is configurable. Note that other threads 1002 in additionto the scheduler thread 1007 may request a system event to be logged viaa communication request to the logger thread 1004, such a the externalinterface thread 1010 via a get events request block (block 1242).

Another feature provided for the optical fiber-based wireless system 900by the HEU 902 in this embodiment is calibration. Calibration involvesdetermining the signal strength loss as a result of conversion of theelectrical RF signal to an RoF signal on a downlink and vice versa on anuplink and compensating for such losses. Signal strength loss can beencountered on the downlink communication path when incoming electricalRF signals from the BTSs 956 provided to the downlink BIC 949 areconverted to RoF signals in the OIMs 910 and communicated to the RAUs906. Gains in the various components in the communication path betweenthe BTSs 956 and the RAUs 906 can be adjusted to compensate for suchlosses. Calibration can also involve determining the signal strengthloss encountered on the uplink communication path. Signal strengthlosses can also be incurred when incoming electrical RF signals to theRAUs 906 are converted to RoF signals and communicated to the OIMs 910,which are converted back to electrical RF signals to communicate suchsignals to the uplink BIC 950. As provided for the downlinkcommunication path, gains in the various components in the communicationpath between the RAUs 906 and the BTSs 956 can also be adjusted tocompensate for such losses. Typically, the gain is set to increase thepower level of the signals communicated in the downlink and uplinkcommunication paths, although the gains could be set to decrease thesignal strength. For example, it may be desirable to normalize thesignal strengths between the various signal inputs among different BTSinputs 957 (FIG. 25A) provided to the downlink BIC 949 to provideconsistency in signal strength among different communication frequenciesfrom different BTS inputs 957.

To facilitate further discussion of calibration, the schematic diagramsof FIGS. 38A-38B are provided to illustrate the optical fiber-basedwireless system 900 and its components involved in calibration,including the HEU 902, the downlink BIC 949, the uplink BIC 950, theOIMs 910, and the RAUs 906, and the RF communication links FIGS. 38A-38Billustrate the downlinks or the downlink communication path 1250 ofincoming electrical RF signals 1252 from the BTSs 956 input into thedownlink BIC 949 and communicated from the downlink BIC 949 to the OIMs910 and RAUs 906 and their various components. As illustrated in FIG.38A, the downlink communication path 1250 is split into parallelcommunication paths between the downlink BIC 949 and the OIMs 910 via asplitter 1251. As previously discussed, up to twelve (12) OIMs 910 maybe coupled to a downlink BIC 949 in this embodiment (hence the 1:12designation in FIG. 38A). Further, as illustrated in FIGS. 38A-38B, thedownlink communication path 1250 is further split into parallelcommunication paths between the OIMs 910 and the RAUs 906. As previouslydiscussed, up to three (3) RAUs 906 may be coupled to each OIM 910 inthis embodiment. Further, FIGS. 38A-38B illustrate the uplinks uplinkcommunication path 1254 of incoming electrical RF signals 1256 from theRAU antennas 905 input into the RAUs 906 and communicated from the RAUs906 to the OIMs 910 and the uplink BIC 950 and their various components.

To calibrate the optical fiber-based wireless system 900 and itscomponents in this embodiment, two calibration oscillators 1258A, 1258Bare provided in the downlink BIC 949, as illustrated in FIG. 38A. Thecalibration oscillators 1258A, 1258B are provided to generate twoindependent electrical calibration signals 1260A, 1260B at expectedpower levels or signal strengths at two different frequencies in orderto calibrate the optical fiber-based wireless system 900 for twodifferent frequencies in this embodiment. The calibration signals 1260A,1260B are each provided to frequency switches 1262A, 1262B that areunder control of the downlink BIC microprocessor 965. In this manner,the downlink BIC microprocessor 965 can switch the frequency switches1262A, 1262B on when desired or when instructed by the HEU controller958 when in a calibration mode to assert or inject the calibrationsignals 1260A, 1260B onto the downlink communication path 1250.Calibration involves providing the calibration signals 1260A, 1260B intocouplers 1264 for each of the four BTS inputs 957 in this embodiment.

In this embodiment, the HEU microprocessor 960 can instruct the downlinkBIC microprocessor 965 to switch the frequency switches 1262A, 1262B viaI²C communications between the HEU microprocessor 960 and the downlinkBIC microprocessor 965. This calibration action or mode propagates thecalibration signals 1260A, 1260B over the downlink communication path1250 through the downlink BIC 949 and its components. In this manner,the calibration signals 1260A, 1260B are downlink calibration signals.The signal strength of the calibration signals 1260A, 1260B are measuredby calibration measuring components 1263A, 1263B for comparison purposesto determine the loss as a result of the conversion of the electrical RFsignals to RoF signals. This signal strength level is the expectedsignal strength for the calibration signals 1260A, 1260B. Thecalibration signals 1260A, 1260B will reach the OIMs 910 and theircomponents, where the calibration signals 1260A, 1260B will be convertedinto RoF signals for communication to the RAUs. 906. The calibrationsignals 1260A, 1260B in this embodiment are carried over the same RFlinks that carry the electrical RF signals so that calibration can beperformed while RF communications are being provided by the HEU 902.

In this embodiment, one calibration frequency is for high frequencycommunication calibration and the other calibration frequency is for lowfrequency communication calibration. For example, the two calibrationfrequencies could be 915 MHz and 2017 MHz. In this manner, the opticalfiber-based wireless system 900 is calibrated for both high and lowfrequency signals. The frequencies of the calibration signals 1260A,1260B are selected in this embodiment to not overlap and thus interferewith the expected frequencies of RF signals communicated over thedownlink communication path 1250 and/or the uplink communication path1254 so that calibration can occur even while RF communications areoccurring and without requiring RF communications to be disabled.However, note that any number of calibration signals 1260 may beemployed and at any frequency or frequencies desired.

Eventually, the RoF signals generated as a result of the OIM's 910receipt and conversion of the calibration signals 1260A, 1260B to RoFsignals will reach the RAUs 906, as illustrated in FIGS. 38A and 38B.The RAUs 906 will convert the RoF signals back into electrical RFsignals before transmitting the signals via the antennas 905. Thus, inthis embodiment, downlink calibration measurement components 1265 areprovided in the RAUs 906 and coupled to the output of final stageamplifiers 1266. The downlink calibration measurement components 1265receive electrical RF signals 1268 representing the calibration signals1260A, 1260B before the electrical RF signals 1268 are communicated tothe antennas 905 in the RAUs 906.

In this regard, the power or signal strength of the electrical RFsignals 1268 can be measured by the downlink calibration measurementcomponents 1265 to be compared against the expected power or signalstrength of the calibration signals 1260A, 1260B as measured by thecalibration measuring components 1263A, 1263B (block 1321). Losses canbe determined as a result of the calibration signals 1260A, 1260B beingpropagated along the downlink communication path 1250. Losses may beincurred due to propagation of the calibration signals 1260A, 1260Bthrough various components in the downlink communication path 1250 aswell as from conversion of the calibration signals 1260A, 1260B fromelectrical RF signals to RoF signals in the OIMs 910. Losses can also beincurred when the RoF signals are converted back to electrical RFsignals in the RAUs 906. Gains can be adjusted in components present inthe downlink communication path 1250 of the optical fiber-based wirelesssystem 900, including but not limited to adjustments to gains inamplifiers and/or attenuators, to compensate for such losses, as will bedescribed in more detail below. As illustrated, the downlinkcommunication path 1250 is split into three bands in this embodiment,although any number may be included. In this embodiment, the gainadjustment for calibration of the downlink communication path 1250 willbe performed in the RAUs 906, as discussed in more detail below.

Similarly, the uplink communication path 1254 can also be calibrated tocompensate for losses incurred from converting received electrical RFsignals 1270 from the antennas 905 of the RAUs 906 on the uplinkcommunication path 1254 into RoF signals 1254. Losses can be incurred byconverting the received electrical RF signals 1270 to RoF signals in theRAUs 906 and back to electrical RF signals in the OIMs 910 before beingcommunicated to the uplink BIC 950. Gain adjustments can also be made tocompensate for these losses in the uplink communication path 1254 in theoptical fiber-based wireless system 900. In this regard, the samecalibration signals 1260A, 1260B that are used to calibrate the downlinkcommunication path 1250 can also be used to calibrate the uplinkcommunication path 1254, although such is not required.

As illustrated in FIG. 38C, downlink calibration switches 1274 areprovided in the RAU 906. The downlink calibration switches 1274 receivefiltered electrical RF signals 1277 representative of the calibrationsignals 1260A, 1260B from a downlink multiplexor 1275 to control whethereither the downlink communication path 1250 or the uplink communicationpath 1254 is calibrated. The downlink calibration switches 1274 controlwhether the electrical RF signals 1277 representative of the calibrationsignals 1260A, 1260B are directed in the downlink communication path1250 to an antenna multiplexer 1275 in the RAU 906 to calibrate thedownlink communication path 1250, or to RAU band amplifiers 1276 in theuplink communication path 1254 to calibrate the uplink communicationpath 1254 (labeled signals 1268). If directed to the uplinkcommunication path 1254, the calibration signals 1260A, 1260B are alsouplink calibration signals. The power of the signals 1268 will bemeasured by measurement calibration components 1279 to determine theexpected signal strength for comparison purposes and calibration tooffset any losses desired. The electrical RF signals 1268 will beconverted back to RoF signals 1278 by an E/O converter 1280 in the OIM910, as illustrated in FIG. 38B. When calibrating the uplinkcommunication path 1254, calibration switches 1282 will be switched todirect the RoF signals 1278 and to communicate the RoF signals 1278 tothe UL BIC 950.

Alternatively, instead of the calibration signals 1260A, 1260B beingredirected to the uplink communication path 1254 to calibrate the uplinkas discussed above, uplink calibration signal generators separate fromthe calibration oscillators 1258A, 1258B. It may be desirable to provideseparate uplink calibration signal generators if the losses in thedownlinks cause the signal strength of the calibration signals 1260A,1260B to be too weak for use to measure losses on the uplinks, as oneexample. In this regard, uplink calibration oscillators could beemployed in the RAUs 910 to generate uplink calibration signals overtthe uplink communication path 1254 to determine the losses on theuplinks. The signal strength of the uplink calibration signals could bemeasured in the RAUs 910 and then measured as the UL-BIC 950, just asdescribed above, to calculate the loss in the uplinks.

The RoF signals 1278 on the uplink communication path 1254 will reachthe uplink BIC 950, as illustrated in FIG. 38A. In this embodiment,uplink calibration measurement components 1284 are provided in theuplink BIC 950 and coupled to the output of uplink calibration frequencyswitches 1286, which are coupled to the final output stage of the uplinkBIC 950. The uplink calibration measurement components 1284 receiveelectrical RF signals 1287 representing the calibration signals 1260A,1260B. In this regard, the power or signal strength of the electrical RFsignals 1287 can be measured by the uplink calibration measurementcomponents 1284 to be compared against the expected power or signalstrength of the calibration signals 1260A, 1260B. Losses can then bedetermined as a result of the calibration signals 1260A, 1260B beingpropagated along the uplink communication path 1254. Losses may beincurred due to propagation of the calibration signals 1260A, 1260Bthrough various components in the uplink communication path 1254 as wellas from conversion of the calibration signals 1260A, 1260B from RoFsignals to electrical signals in the OIMs 910. Like the downlinkcommunication path 1250, gains can be adjusted in components of theoptical fiber-based wireless system 900 in the uplink communication path1254 to compensate for such losses, as will be described in more detailbelow. In this embodiment, the gain adjustment for calibration of theuplink communication path 1254 will be performed in the OIMs 910, asdiscussed in more detail below.

The calibration of the optical fiber-based wireless system 900 isperformed for each of the calibration oscillators 1258A, 1258B in thisembodiment. Further, the calibration of the optical fiber-based wirelesssystem 900 may be performed for each of the four (4) possible BTS inputs957, for up to a total of thirty-six (36) possible RAUs 906 (i.e., three(3) bands times twelve (12) OIMs 910 times three (3) RAUs 906 per OIM910). This involves a possible total of four hundred thirty-two (432)calibration processes for the optical fiber-based wireless system 900 inthis embodiment. By the module discovery process previously describedabove, the calibration performed for the optical fiber-based wirelesssystem 900 will automatically and adaptively be performed and adapted tothe downlink and uplink communication paths 1250, 1254 and the OIMs 910and RAUs 906 present. Thus, if temperature variations or an aging effectcause changes in the gain or loss of the components, recalibration ofthe OIMs 910 and RAUs 906 will account for such changes automaticallyand periodically. Gain adjustments made in the RAUs 906 as part of thegain adjustment during calibration will only affect the individual RAU906 and not other RAUs 906.

To allow the HEU controller 958 to control the calibration process, thecalibration thread 1008 is provided in the HEU controller 958 andexecuted by the HEU microprocessor 960. The calibration thread 1008 waspreviously introduced and illustrated in FIG. 30. The calibration thread1008 is provided to initiate and control calibration of the HEU 902 andits components, which includes the OIMs 910 and the RAUs 906 in thisembodiment. The calibration thread 1008 makes calls that cause the HEUcontroller 958 to instruct the downlink BIC 949 (e.g., via I²Ccommunications) to switch the frequency switches 1262A, 1262B togenerate the calibration signals 1260A, 1260B. Likewise, themeasurements made by the downlink and uplink calibration measurementcomponents 1265, 1284 from the RAUs 906 for the downlink communicationpath 1250 and from the uplink BIC 950 for the uplink communication path1254, respectively, can be provided to the HEU controller 958 and thescheduler thread 1007 to make decisions regarding gain adjustments.

In this regard, FIGS. 39A and 39B illustrate an exemplary flowchartproviding the process carried out by the calibration thread 1008 in theHEU controller 958 in this embodiment. FIGS. 39A and 39B are discussedin conjunction with the component diagrams of the optical fiber-basedwireless system 900 in FIGS. 38A-38B, which illustrated the components,including the HEU 902, the downlink BIC 949, the uplink BIC 950, theOIMs 910, and the RAUs 906. The calibration thread 1008 performs acalibration loop 1300. The first step performed by the calibrationthread 1008 is to wait for the next time to perform the calibrationprocess (block 1302). The HEU controller 958 can be configured tocustomize how often the calibration process and the calibration loop1300 in the calibration thread 1008 is performed. Thus, the HEUcontroller 958 can be configured to perform calibration periodically andautomatically without the need for a manual start, such as by directiveof a technician. When the calibration process is to be performed, thecalibration thread 1008 selects the next communication band to use tocalibrate the optical fiber-based wireless system 900 (block 1304). Aspreviously discussed, in this embodiment, one of two frequency bands isselected by selecting one of the two frequency switches 1262A, 1262Bthat control which calibration signal 1260A, 1260B is asserted on thedownlink communication path 1250 in the downlink BIC 949, as illustratedin FIG. 38A. Next, the calibration thread 1008 selects the next RAU 906to calibrate for the downlink calibration (block 1306). In thisembodiment, only one RAU 906 is calibrated at one time since each RAU906 provides its own unique downlink communication path 1250 once thecommon portion of the downlink communication path 1250 is split todifferent OIMs 910 by the downlink BIC 949 and then split to differentRAUs 906 from the different OIMs 910.

With continuing reference to FIG. 39A, the calibration thread 1008selects the next BTS 956 to be calibrated among the four (4) BTS inputs957 provided in this embodiment (block 1308). Thus, each discovered andinitialized RAU 906 is calibrated for each of the four (4) BTS inputs957 for each of the two (2) frequencies of the calibration signals1260A, 1260B in this embodiment (e.g., up to two hundred eighty-eighty(288) calibration processes from thirty-six (36) RAUs 906 times four (4)BTS inputs 957 times two (2) calibration bands). In this regard, thecalibration thread 1008 provides three nested loops (blocks 1304, 1306,1308) in this embodiment to provide each of these calibrationpermutations for the RAUs 906. Next, the calibration thread 1008 isready to perform calibration (block 1310). The calibration thread 1008instructs the HEU controller 958 to send a message to the downlink BIC949 (block 1312). As previously discussed, this involves sending an I²Ccommunication message from the HEU controller 958 to the downlink BICmicroprocessor 965. The downlink BIC 949, via the downlink BICmicroprocessor 965, will next set up the frequency switch 1262 of thetarget calibration oscillator 1258 to the target BTS input 957 (block1314) and enable the desired calibration oscillator 1258 (block 1318)and frequency switch 1262 (block 1320) to generate the calibrationsignal 1260 at the desired calibration band. Note that in thisembodiment, when one calibration oscillator 1258 is selected, the othercalibration oscillator 1258 is automatically switched off and does notrequire a separate command to be disabled.

The signal strength of the calibration signal 1260 is measured by 1263A,1263B. The downlink BIC microprocessor 965 will send an acknowledgement(ACK) message back to the HEU controller 958 to acknowledge receipt ofthe calibration message (block 1322).

When the acknowledgement message is received by the calibration thread1008 from the downlink BIC 949 (block 1324), the calibration thread 1008next issues a calibration request for the selected calibration band tothe selected RAU 906 (block 1326). The selected RAU 906, and moreparticularly the RAU microprocessor 977 in this embodiment (see FIG.38B), to be calibrated receives the calibration request from the HEUcontroller 958 to initiate the calibration process (block 1328). The RAUmicroprocessor 977 of the selected RAU 906 will set the downlinkcalibration switches 1272 (FIG. 38B) to send the electrical RF signalsrepresentative of the calibration signal 1260 to the antenna multiplexor1275 to calibrate the downlink communication path 1250 for the selectedRAU 906, as previously discussed (block 1330). Next, the selected RAU906 will read the signal strength from the downlink calibrationmeasurement components 1265 to determine the downlink communication path1250 loss for the selected RAU 906 (block 1332).

Next, the uplink communication path 1254 involving the selected RAU 906is calibrated. In this regard, the selected RAU 906 switches thedownlink calibration switches 1272 to send the electrical RF signalsrepresentative of the calibration signal 1260 to the RAU band amplifiers1276 for uplink calibration, as previously discussed (block 1338). Thecalibration measurement components 1276 measure the expected signalstrength (block 1339). The selected RAU 906 then sends anacknowledgement (ACK) message back to the HEU controller 958 to indicatethat the downlink calibration process is complete (blocks 1340, 1342).Thereafter, as illustrated in FIG. 39B, the calibration thread 1008sends a calibration request for the selected calibration band to the OIM910 supporting the selected RAU 906 (block 1344). The OIM microprocessor973 for the selected OIM 910 receives the calibration request (block1346) and sets the unused uplink calibration switches 1282 off and setsthe used uplink calibration switch 1282 on (blocks 1348, 1350). This isbecause only one uplink communication path 1254 in the OIM 910 supportsthe selected RAU 906. Thereafter, the selected OIM 910 sends anacknowledgement (ACK) message to the HEU controller 958 (block 1352).When received (block 1354), the calibration thread 1008 sends acalibration request for the selected BTS input 957 and calibration bandto the uplink BIC 950 (block 1356).

The uplink BIC 950 receives the calibration request from the HEUcontroller 958 (block 1358). The uplink BIC 950 sets the uplinkcalibration frequency switches 1286 to the selected BTS input 957 (block1360). The signal strength of the calibration signal is then measuredand the loss calculated using the uplink calibration measurementcomponent 1284 (blocks 1362, 1364). The uplink BIC 950 then sends anacknowledgement (ACK) return message to the HEU controller 958 alongwith the calculated loss (blocks 1366, 1368). The HEU controller 958then sends a request for setting the downlink calibration switches 1274to the downlink (block 1369) to set up the next calibration loop, inwhich case the RAU 906 receives the message and sets the RAU calibrationswitch 1274 to the downlink setting (block 1371). The calibration thread1008 then returns to calibrate the other BTS inputs 957 (block 1384).Thereafter, RAUs 906 are selected for the BTS inputs 957 until alldiscovered and initialized RAUs 906 are calibrated for the selectedcalibration band (block 1386). Then, the same process is repeated forthe previously unselected calibration band (block 1388) to complete thecalibration loop 1300.

When calculations in the required attenuations for the downlink (block1391 in FIG. 39B), the total error for each downlink from the DL-BIC 949to each RAU 906 is determined and stored. The total error for thecommunication downlinks in this embodiment is the input calibrationsignal strength (block 1321 in FIG. 39A) minus the end downlinkcalibration signal strength (block 1332 in FIG. 39A), and minus theinitial gain set for the BTS input 957 by the user (default is 0 dBm inthis embodiment) and minus any calibration offset configured in theDL-BIC 949 and RAU 906 selected. The total error is calculated for alldownlink paths for all enabled BTS inputs 957. Next, the errorattributed across all BTS inputs 957, the BTS error, is determined bydetermining the least common error across all losses for all downlinkpaths for all enabled BTS inputs 957. In this manner, the attenuator(s)in the DL-BIC 949 can be set to compensate for the loss attributed tothe BTS inputs 957 such that this error is not compensated in RAUs 906that have distinct paths in the downlink. The loss attributed to the BTSinputs 957 is then subtracted from the total loss calculated for eachcommunication downlink path for all enabled BTS inputs 957 to determinethe error attributed to the RAUs 906. The RAU 906 attenuation levels arethen calculated from this remaining communication downlink error foreach BTS input 957 for all enabled RAUs 906. For example, a weightedaverage loss or median loss for each RAU 906 for each enabled BTS input957 may be used to determine the attenuation levels for each RAU 906.Values outside a given threshold tolerance may be discarded as incorrectvalues or indicative of other errors, which may generate an alarm.

The total error for each communication uplink from each RAU 906 to theUL-BIC 950 is determined and stored in a similar manner to thedownlinks. The total error for the uplinks in this embodiment is theinput calibration signal strength (block 1321 in FIG. 39A) minus the enduplink calibration signal strength (block 1364 in FIG. 39B), and minusthe initial gain set for the a BTS input 957 by the user (default is 0dBm in this embodiment) and minus any calibration offset configured inthe UL-BIC 950 and OIM 910 selected. The total error is calculated forall uplink paths for all enabled BTS inputs 957. Next, the errorattributed to all BTS inputs 957 is determined by determining the leastcommon error across all losses for all downlink paths for all enabledBTS inputs 957. In this manner, the attenuator(s) in the UL-BIC 950 canbe set to compensate for the loss attributed to the BTS inputs 957 suchthat this error is not compensated in OIMs 910 having distinct paths inthe uplink. The loss attributed to the BTS inputs 957 is then subtractedfrom the total loss calculated for each uplink path for all enabled BTSinputs 957 to determine the error attributed to the OIMs 910. The OIM910 attenuation levels are then calculated from this remaining error foreach BTS input 957 for all enabled OIMs 910. For example, a weightedaverage loss or median loss for each OIM 910 for each enabled BTS input957 may be used to determine the attenuation levels for each OIM 910.Values outside a given threshold tolerance may be discarded as incorrectvalues or indicative of other errors, which may generate an alarm.

When the attenuations levels are calculated, the attenuation levels canbe applied, as illustrated in block 1392 in FIG. 39B. When multiple RAUs906 are provided, an order of setting attenuators can be as follows: theDL-BIC 949 attenuators, the UL-BIC attenuators 950, the RAU 910attenuators for all BTS inputs 957 on the downlink, and the OIM 910attenuators for all BTS inputs 957 on the uplink. Further, alternativeembodiments include not setting the attenuators to correct for theentire calculated error so that overshoot is not corrected inattenuation levels and/or to prevent intermittent noise from moving linkgain to a much higher or lower value in a single calibration calculationiteration. For example, if an error is calculated, the attenuators maybe compensated by increase or decrease in increments, for example, 1 dBmper calculation. Further, calibration may only be performed for one BTSinput 957 or less than all BTS inputs 957. Attenuation levels may be setto maximum thresholds to minimize impact to shared links in thedownlinks and uplinks.

The calibration thread 1008 checks to see if calibration has been turnedoff before repeating (block 1389), in which case it is turned off (block1390). If calibrations are required, they are calculated (block 1391)and applied to the attenuators (block 1392). For the downlinks, the RAUmicroprocessor 977 can set the gain of two RAU attenuators 1336A, 1336B(FIG. 38B) and attenuators 1253 in the downlink BIC 949 to compensatefor calculated losses from actual versus expected signal strengths afterwhich the downlink communication path 1250 for the selected RAU 906 iscalibrated. Similarly, the calibration thread 1008 calculates theattenuation for the selected OIM 910 to compensate for the loss in theuplink communication path 1254 (block 1391). The calibration thread 1008then sends the attenuation settings to the selected OIM 910, which inturn sets the OIM 910 attenuation by setting the attenuation of theattenuators 1376A, 1376B (FIG. 38B) in the uplink communication path1254 for the selected RAU 906 and in the attenuators 1287 in the uplinkBIC 950.

As previously discussed, the embodiment of the HEU 902 is configured tosupport up to thirty-six (36) RAU s 906, via up to twelve (12) OIMs 910supporting up to three (3) RAUs 906 each. However, in certainconfigurations, more than thirty-six (36) RAUs 906 may be needed ordesired to provide the desired coverage areas. For example, the RAUs 906may provide picocellular coverage areas. In this regard, a plurality ofHEUs 902 may be provided 902A, 902B, 902N as illustrated in FIG. 40. Inthis example, one HEU 902A is configured as a master HEU with other HEUs902B, 902N provided as slave units off of the master HEU 902A. The slaveHEUs 902B, 902N are coupled to the master HEU 902A, and moreparticularly, the HEU controller 958A, via a private network 1400. Theprivate network 1400 may be provided as any type of communication linkand according to any protocol desired, such as Transport CommunicationProtocol (TCP)/Internet Protocol (IP), as an example. Each HEU 902A,902B, 902N may be configured with its own TCP/IP address that supportsdata packet communications. In this manner, clients 920 can communicateover a customer network 914 with the master HEU 902A to not onlyretrieve and configure information from the master HEU 902A and the RAUs906A, but also the slave HEUs 902B, 902N and RAUs 906B, 906N. The slaveHEUs 902B, 902N and RAUs 906B, 906N are only accessible by clients 920from the master HEU 902 in this embodiment.

FIG. 41A illustrates a similar HEU configuration to FIG. 40, except thata gateway/firewall 1402 is installed between the customer network 914and the master HEU 902A. The gateway/firewall 1402 may allow private IPaddresses between the master HEU 902A and the slave HEUs 902B, 902N onthe private network 1400 and one public IP address to access the masterHEU 902A via the customer network 914 (FIG. 24). The master HEU 902A mayalso employ Dynamic Host Configuration Protocol (DHCP) to assign privateIP addresses to the slave HEUs 902B, 902N.

FIGS. 41B and 41C also illustrate configurations employing multiple HEUs902. In FIG. 41B, each HEU 902 is connected and accessible on thecustomer network 914. Thus, both HEUs 902 are master units that eachoperate independently of each other. Still this embodiment, allowsclients access from one master HEUs 902 to all other HEUs 902 on thecustomer network 914. The customer network 914 has to access each HEU902 in FIG. 41B independently. In FIG. 41C, a configuration is providedthat is a hybrid configuration of the configurations in both FIGS. 41Aand 41B. In FIG. 41C, multiple master HEUs 902A′, 902A″ are providedthat are each accessible over the customer network 914. Each master HEU902A′, 902A″ is coupled to its own private network 1400′, 1400″ tocommunicate with slave HEUs 902B′, 902N′, 902B″, 902N″, respectively.Thus, as illustrated in FIGS. 40-41C, multiple configurations involvingmultiple HEUs 902 are possible and can be provided to configure theoptical fiber-based wireless system(s) 900 in different configurations.

As previously discussed and illustrated in FIGS. 24, 25, and 30, the HEU902 is configured to provide the external interface services via theexternal interface thread 1010. The external interface thread 1010supports both the web server 940 for web browser interfacing and theSNMP agent 942 for interfacing to the SNMP server 920. The externalinterface thread 1010 allows access to data that has been previouslydescribed above regarding the optical fiber-based wireless system 900.For example, as illustrated in FIG. 30, the external interface thread1010 includes an external interface queue that receives messages fromother threads 1002 in the HEU controller 958 in this regard. Forexample, the logger thread 1004 sends communication messages to theexternal interface thread 1010 to report alarms, system events, errors,to calibrate and/or restart the HEU controller 958 and/or its threads1002, etc. The HEU controller process 1001 also sends messages to theexternal interface thread 1010. The SNMP agent 942 and web server 940can also be directly accessed via the external interface manager module974. The external interface thread 1010 also has direct access todatastore 966 to be able to obtain information stored in datastore 966by the other threads 1002, including points and point information andmodule configurations. Some of these features will be discussed now inmore detail by example of the web server 940 in the HEU 902. Aspreviously discussed, the web server 940 allows the ability for webclients 920 to access the HEU 902 and the HEU controller 958.

The web server 940 in this embodiment can support a number of thepreviously described features provided in the HEU 902. For example, theweb server 940 can allow a client 920 to configure the HEU 902. Thisincludes enabling or disabling BTS 956 bands, adjusting BTS input 957power levels, and setting gains for RAUs 906. The web server 940 in thisembodiment also allows configuring network addresses for the HEU 902,user access management, saving the configuration of the HEU 902 to anexternal file or uploading a configuration from a file, configuring theSNMP interface, and managing floor plans for the optical fiber-basedwireless system 900.

The web server 940 also allows a client 920 to monitor the overallstatus of the optical fiber-based wireless system 900. The client 920can view the status of the points by allowing access to the point list993. The web server 940 also allows a client 920 to set properties forthe points. The web server 940 allows client 920 access to alarms andlogs reported by the HEU controller 958. The web server 940 also allowsa client 920 to upgrade firmware or software for the variousmicroprocessor-based components of the optical fiber-based wirelesssystem 900. These same features and services can also be provided by theSNMP agent 942.

In this regard, FIGS. 42-48 illustrate exemplary web browser graphicaluser interface (GUI) screens that are supported by the web server 940 inthis embodiment to allow web clients 920 to access the HEU 902 and toperform various features and functions. FIG. 42 illustrates a login page1500 displayed on the browser of a client 920 that may be provided bythe web server 940 to the client 920 when the IP address of the HEU 902is accessed by the client 920. The web server 940 may require a username and password that has been previously established in the web server940 and stored in a user name and password list in datastore 966 beforegranting a client 920 access to further features for the HEU 902provided by the web server 940. A user would type in their user name inthe user name box 1502 and their corresponding password in the passwordbox 1504 and select the “Login” button 1506 on the login page 1500 tolog into the HEU 902. The web server 940 will authenticate the user nameand password before granting further access to the client 920. The webserver 940 may support different types of logins with differentauthorization or access ability.

FIG. 43 illustrates a various categories of access to the HEU 902. Thename of the user currently logged in is displayed in a user login namearea 1511. If the user desires to log out, the user can select the “SignOut” link 1513. A banner 1512 is provided on the left-hand side of thepage 1510 that illustrates the current optical fiber-based wirelesssystems (“IDAS System”) currently provided in a hierarchal or treestructure. For example, underneath an IDAS System heading 1514, thereare five (5) HEUs 1516 listed. An expansion button 1518 by the IDASSystem heading 1514 can be selected to show the HEUs 1516 included inthe system. Each of the HEUs 1516 can be given customer names, ifdesired, which can be alias names. As will be described in more detailbelow, expansion buttons 1520 are also provided beside each HEU 1516 tofurther expand access to modules in the HEU 1516, which in this casewould be discovered and initialized OIMs 910. OIMs 910 can be expandedto show discovered and initialized RAUs 906 coupled to the OIMs 910.Selection boxes 1522, 1524 allow selection of the desired HEUs 1516.Operations performed in a feature section 1525 of the default page 1510will be performed on selected devices or modules. If the selection box1522 for the IDAS System is checked, the selection boxes 1524 for HEUs1516 therein will be checked automatically. However, each HEU 1516 canbe unchecked or checked individually as desired.

The status of each HEU 1516 is shown in a status icon 1526 to provide avisual status indication of the component shown, which in this exampleis an HEU 902. For example, the status icons 1526 could be color coded.A green color could indicate no errors or warning for the HEU 902 andits components in this embodiment. A yellow color could indicate that atleast one warning is present for the HEU 902 in this embodiment. A redcolor could indicate a critical error is present for the HEU 902 in thisembodiment. Beside the status icons 1526 are flags 1528 that areprovided if a component within the HEU 902 has a fault, which in thiscase would be either an OIM 910 or a RAU 906. The feature section 1526includes a banner 1530 that provides the various functions and featuresmade available to the client 920 with regard to the selected HEU(s) 902or modules. The “System Status” tab 1532 can be selected to view thestatus of a selected HEU 902. The “Config” tab 1534 can be selected toconfigure certain aspects of the HEU 902 or its modules. The “Monitor”tab 1536 can be selected to monitor the selected HEU 902 and its modulesthat have been discovered and initialized. The “Alarms” tab 1538 can beselected to view alarms either reported by the modules or calculated bythe scheduler thread 1007 in an HEU controller 958. The “Logs” tab 1540can be selected to view the log of system events recorded by the loggerthread 1004 in a HEU controller 958. The “Properties” tab 1542 can beselected to provide certain properties about selected HEUs 902 or othercomponents. The “Installation” tab 1544 can be selected to provideinformation about installation. The “Service Status” tab 1546 can beselected to view the overall status of a selected HEU 902 or module. The“System Information” tab 1547 can be selected to display a table ofmodule information for each detected module in the HEU 902 and RAUs 906connected thereto. Each of the features available through the externalinterface functionality of the HEU 902 will be discussed in more detailbelow. A tracer event can also be displayed in the trace message section1527.

FIG. 44 illustrates the default page 1510 when the “System Notes” tab1532 has been selected by a client 920. The default page 1510 is alsodisplayed as the initial page after a user has logged in. Asillustrated, the overall or “snapshot” of the system status is providedin a “System Status” area 1550. If RF communication has been enabled, an“RF Enabled” check box 1552 is selected. RF communications can bedisabled by unselecting the “RF Enabled” check box 1552 if suchpermission is granted to the user, otherwise the “RF Enabled” check box1552 will be unselectable. The number of faulty HEUs 902, OIMs 910, andRAUs 906 are listed in a “Faulty” section 1554, meaning these componentsare at fault. The number of degraded components is also listed in a“Degraded” section 1556, meaning a fault condition exists, but thecomponents may be operational. The number of operational componentswithout faults are listed in a “Working” section 1558. The detailsregarding the installer and primary and secondary contacts can bedisplayed in an installation area 1560. This information can be editedby selecting the “Edit” link 1562. Notes regarding the last service aredisplayed in a “Service” area 1564. Service notes entered by a servicetechnician can be displayed by selecting the “View Service Notes” link1566. The service manual can be viewed by selecting the “View ServiceManual” link 1568. If more information regarding identifying which HEUs902, OIMs 910, and RAUs 906 in particular are at fault, the expansionbuttons 1520 can be selected to expand and display the OIMs 910 for eachexpanded HEU 902 in the banner 1512, as illustrated in FIG. 45.Expansion buttons 1570 for each OIM 910 can be further selected todisplay the RAUs 906 for each expanded OIM 910. Status icons 1526 andstatus flags 1528 are displayed beside the modules that contain warningor errors. Status flags 1528 are not displayed beside the RAUs 906,because the RAUs 906 have no further sub-components that are tracked forerrors at the system level accessible externally through the HEU 902.

FIG. 46 illustrates an exemplary configuration page displayed on aclient's 920 web browser when a “HEU BTS Config” tab 1579 has beenselected under the “Config” tab 1534. The HEU 902 supports the abilityof a client 920 to configure certain aspects of the HEU 902.Configuration can involve configuring the HEU 902 and configuring thecommunications links for the HEU 902. For example, as illustrated inFIG. 46, the web server 940 allows the client 920 to enable or disableBTS inputs 957 for selected HEUs 902 in the banner 1512 by selecting aBTS input enable box 1580 for each BTS input 957 (i.e., BTS 1, BTS 2,BTS 3, BTS 4). If the BTS input enable box 1580 is not selected for aparticular BTS input 957, the BTS input power for such BTS input 957 isdefaulted to 0 dBm in this embodiment. If the BTS input enable box 1580is enabled, the maximum input power or gain (in dBm) for the BTS inputs957 can be provided by typing a number in an input power input box 1582.The BTS inputs 957 may be limited, for example, between −10 and 30 dBm,with 30 dBm being the maximum input power. Different BTS inputs 957 maybe provided by different carriers or service providers and may benormalized for this reason via configuration. Uplink BIC ports may alsobe limited for maximum power input although not configurable by a clientin this embodiment. Thereafter, the new configuration can be committedby selecting a “Commit Configuration” button 1584, which will then causethe HEU controller 958 to apply the power level settings to the BTSinputs 957 for the RAUs 906 per BTS input band. The gain level willaffect the calibration of the links. Alternatively, by selecting a“Revert to Actual Values” button 1586, the previously committed inputpower values will be retained and displayed in the input power inputboxes 1582 for the RAUs 906 for the selected HEUs 902.

FIG. 47A illustrates an exemplary configuration page displayed on aclient's 920 web browser when a “Link “Config” tab 1590 has beenselected. The HEU 902 supports the ability of a client 920 to configurelinks for the HEU 902. For example, as illustrated in FIG. 47A, the webserver 940 allows, as an option, the client 920 to select an advancedview by selecting an “Advanced View” selection box 1592. If selected,separate gains for uplinks and downlinks can be provided, otherwise onlyone gain setting is allowed for both the downlink and uplink of a givenband. In response, the possible bands that can be enabled will bedisplayed in a band display area 1594. Each band can be enabled ordisabled by selecting or deselecting “Enable Band” selection boxes 1596.The uplink gain and downlink gain (in dB) can be set by the client 920for enabled bands by typing in the desired gains in an “Uplink Gain”input box 1598 and a “Downlink Gain” input box 1600 for each band.Warnings can be ignored if configuring a locked RAU 906 by selecting anignore warning selection box 1602. The link configuration for the RAUs906 can be locked after a link configuration has been committed byselecting a lock RAUs section box 1604. Locking the configuration locksthe gain for the RAUs 906 and other set values such that they cannot bechanged without unlocking and proper authorization. These linkconfigurations can be committed by selecting a “Commit Configuration”button 1606, which will then cause the HEU controller 958 to apply thelink configurations to the RAUs 906, as previously discussed (see FIG.38B). Alternatively, by selecting a “Revert to Actual Values” button1608, the previously committed link configurations will be retained anddisplayed. When a module is selected, if an alarm is already present, itcan be displayed and viewed.

FIG. 47B illustrates an exemplary users page displayed on a client's 920web browser when the “Users” tab 1535 under the “Config” tab 1534 hasbeen selected. This allows authorized users to be created and provides alist of established users. The “Users” tab 1535 may be restricted basedon the permission level for the current user. In this regard, an “AddUser” section 1537 is provided whereby a new user can be added. A username 1539 and password 1541, 1543 can be entered for an added user. Adescription 1545 for the added user and a permissions setting 1547 forthe added user can be selected. Different permissions can be selected tocontrol various accesses to the HEU controller 958 and itsfunctionality. Once the information for the new user is provided, theuser information can be saved by selected a “SAVE USER” button 1549 orthe addition of the user can be cancelled by selecting a “CANCEL” button1551. If it is desired to edit or delete a previously added user, ausers list 1553 is displayed wherein any of the users can be selected.For example, a user with the user name “IDAS” is selected in the userslist 1553. The user can be deleted by selecting a delete button 1555, ifdesired.

FIG. 47C illustrates an exemplary engineering page displayed on aclient's 920 web browser when the “Engineering” tab 1557 under the“Config” tab 1534 has been selected. This allows point information thatis configurable to be edited by a user to be edited. For points formodules, as indicated by the module name 1559 and point name 1561, theraw value 1563, slope value 1565, and offset value 1567 of the point canbe edited by a user. The raw value 1563 sets the VALUE bit in theflagbits 999, as previously discussed and illustrated in FIG. 29. Theslope value 1565 and offset value 1567 set the STEP SIZE and OFFSET bitsin the flagbits 999, as previously discussed and illustrated in FIG. 29.If it is desired to see the current value of the raw value 1563, slopevalue 1565, and offset value 1567, a get value button 1569 can beselected, in which case these values are displayed to the user. To setthe raw value 1563, slope value 1565, and offset value 1567 to thevalues entered by the user, a set value button 1571, set slope button1573, and set offset button 1575 can be selected, respectively, whereinthe HEU controller 958 will update such information for the selectedpoint name 1561.

FIG. 48 illustrates an exemplary system monitor page displayed on aclient's 920 web browser when the “Monitor” tab 1536 has been selectedand at least one module has been selected. The HEU 902 supports theability of a client 920 to monitor points for the HEU 902. For example,as illustrated in FIG. 48, the web server 940 allows the client 920 tosee a listing 1610 of all points for all modules 1612 by point name1614, the current value of the point 1618, the units 1620, and whetherthe point is writeable 1622 and dynamic 1624.

FIG. 49 illustrates an exemplary system alarm page displayed on aclient's 920 web browser when the “Alarms” tab 1538 has been selected.The HEU 902 supports the ability of a client 920 to see alarms generatedfor the HEU 902. For example, as illustrated in FIG. 49, the web server940 allows the client 920 to see a listing of all alarms 1630 by module1632, point name 1634, current value 1636, units 1638, alarm status1640, threshold 1642, hysteresis 1644, and other characteristics thatmay be provided in the flagbits 999 (FIG. 29).

FIGS. 50A and 50B illustrate an exemplary log page displayed on aclient's 920 web browser when the “Logs” tab 1540 has been selected. TheHEU 902 supports the ability of a client 920 to see logs, which aresystem events, generated for the HEU 902. For example, as illustrated inFIGS. 50A and 50B, the web server 940 as an option allows the client 920to select the logs desired to be viewed by selecting an option in a“Scope of Log View” selection drop down menu 1650. Optional radiobuttons 1652, 1654, 1656, and 1658 can be selected individually to see alist of all logs, critical faults only, system events only, or warningevents only, respectively. The logs, whichever options are selected, aredisplayed in a listing 1660 on the default page 1510.

FIG. 51A illustrates an exemplary properties page displayed on aclient's 920 web browser when the “Properties” tab 1542 has beenselected. The HEU 902, and more particularly, the HEU controller 958,supports the ability of a client 920 to see and provide properties forselected components in the banner 1512. These properties may be usefulto store information about the HEUs 902 and their components formaintenance or other reasons. For example, as illustrated in FIG. 51A,the name of the selected component is provide in a “System ComponentName” box 1680. A nickname can be added or modified in a “CustomerAssigned NickName” input box 1682. A serial number and hardware model ofthe selected component can be provided in a “Serial Number” input box1684 and a “Hardware Model” input box 1686, respectively. A hardwarerevision number and firmware revision number are displayed in a readonly in a “Hardware Rev” input box 1688 and a “Firmware Rev” input box1690, respectively. A customer assigned location can be provided in a“Customer Assigned Location” input box 1692. If it is desired to providea picture or graphic of a system configuration (e.g., flow plan), abitmap can be provided by providing a bitmap name in a “Location BitmapName” input box 1694. A “Browse” button 1696 allows browsing ofdirectories and file names to select the desired bitmap file. Theselected component can be identified in particular on the bitmap byproviding an X and Y coordinate in X and Y input boxes 1698, 1700.

FIG. 51B illustrates an exemplary systems information page displayed ona client's 920 web browser when the “Installation” tab 1544 has beenselected. The HEU controller 958 supports the ability of a user toprovide installation information regarding the installer for aparticular installation for the HEU 902. In this manner, users can pullup this information to contact the installer, if desired. In thisregard, the installer's name 1703, address 1705, city, state, and zipcode 1707, and website address 1709 can be provided as illustrated inFIG. 51B. A primary contact 1711 and his or her phone number 1713, emailaddress 1715, and logo 1717 can be provided, as well as a secondarycontact 1719 and his or her phone number 1721, email address 1723, andlogo 1725. When additions or changes are completed, the currentconfiguration for the HEU 902 and RAUs 906 can be committed by selectinga commit configuration button 1727, or the HEU controller 958 can revertto actual values of configured information for the HEU 902 and RAUs 906by selecting a revert to actual values button 1729.

FIG. 52 is an exemplary user configuration supported by the HEUcontroller 958 and displayed on a client's 920 web browser. Asillustrated therein, the client 920 can select to configure usersauthorized to access the HEU 902 via the web server 940 by selecting a“Users” tab 1710 under the “Config” tab 1534. The current setup usersare displayed by user id 1712 in a current user's area 1714. Aparticular user can be removed if the current user has sufficientpermission by selecting a “Remove User” 1716 button when the user to beremoved is selected from the current users area 1714. To create a new orupdate or edit a previously established user, a user configuration area1718 is provided. The user's login name can be provided in a “User Name”input box 1720. A description of the user can be provided in a“Description” input box 1722. The user's password and confirmation ofpassword can be provided in a “Password” input box 1724 and a “ConfirmPassword” input box 1726, respectively. The user's privileges can beselected among various privilege settings 1728 illustrated in FIG. 52.All updates can be committed to the HEU 902 by selected a “CommitUpdates” button 1730.

FIG. 53 is an exemplary network setup configuration supported by the HEUcontroller 958 and displayed on a client's 920 web browser for networkaccess to the HEU 902. As illustrated, a client 920 can provide anetwork setup for the HEU 902 by selecting a “Network Setup” tab 1740under the “Config” tab 1534. When selected, network setup options forthe selected HEU 902 will be displayed. The IP address of the HEU 902can either be assigned statically via a static IP address, subnet mask,and default gateway provided in a “Static IP address” input box 1742,“Subnet Mask” input box 1744, and “Default Gateway” input box 1746,respectively. The DHCP server, Domain Name System (DNS) server primaryand DNS server secondary can be provided in a “DHCP Server” input box1748, a “DNS Server Primary” input box 1750, and a “DNS ServerSecondary” input box 1752, respectively. Alternatively, the HEU 902 canbe configured to automatically obtain network settings via DHCP byselecting a radio button 1754. If the HEU 902 is to be configured in aprivate network or master/slave configuration, a support discovery checkbox 1756 can be selected to discover other HEUs 902. The HEUs 902 can beconfigured in the desired configuration, including the configurationspreviously discussed and illustrated in FIGS. 40-41C. All networkconfigurations selected can be committed by selecting a “CommitConfiguration” button 1758. Alternatively, by selecting a “Revert toActual Values” button 1760, the previously committed networkconfigurations will be retained and displayed.

FIG. 54 is an exemplary HEU configuration page supported by the HEUcontroller 958 and displayed on a client's 920 web browser. Asillustrated, a client 920 can provide a System HEU configuration for theHEU 902 by selecting a “System HEUs” tab 1770 under the “Config” tab1534. When selected, HEU system information for the selected HEU 902will be displayed. Manual IP addresses for HEUs 902 to be discovered canbe typed into a “Manual IP Address” input box 1772 and added to a list1774 of configured HEU IP addresses. Alternatively or in addition, selfdiscovered HEUs 902 can be selected from a list 1776 by selecting thedesired self discovered HEU 902 from the list 1776 and adding the HEUaddress to the list 1774 by selecting an “Add HEU Address” button 1778.This is populated if the support discovery check box 1756 in FIG. 53 wasselected. HEU addresses can also be removed by selecting the IP addressto be removed from list 1774 and selecting a “Remove HEU Address” button1780. The software avoids the need for additional customer interfacesoftware running under the customer's control and involving multipletypes of machines, operating systems and environments. IDAS will useindustry standard client interface hosting applications that willinclude a Web browser and Terminal Emulator hardware, and will promotethe selection of industry standard management interfaces.

FIG. 55 is an exemplary service notes page supported by the HEUcontroller 958 and displayed on a client's 920 web browser. The servicenotes allow a technician to enter notes about servicing of the HEU 902so that this information can be stored in a log for later review, ifneeded or desired. In this regard, the user can select the “ServiceNotes” tab 1546. The “Service Notes” tab 1546 may be restricted to onlytechnicians that are authorized to perform service actions on the HEU902. Services notes can be entered in a service notes window 1802,wherein a technician name 1804 and notes 1806 can be entered and savedby selecting a “SAVE” button 1807. If it is desired to clear informationprovided in these fields, a “CLEAR” button 1808 can be selected.Previous service notes entered in order of most recent are displayed ina “Service Notes Log” window 1810.

FIG. 56 is an exemplary system information page supported by the HEUcontroller 958 and displayed on a client's 920 web browser. The systeminformation page allows a technician or user to review information aboutthe HEU 902 and modules. This information may be useful in servicing orupgrading the HEU 902 and other modules. In this regard, the user canselect the “System Information” tab 1547. When selected, a serial number1822, hardware version 1824, and firmware version 1826 for the HEU 902is shown in an HEU window 1828. Module names 1830, and their type 1832,serial number 1834, hardware version 1836, and firmware version 1838 arealso displayed in a modules window 1840.

The optical-fiber based wireless system discussed herein can encompassany type of electronic or fiber optic equipment and any type of opticalconnections and receive any number of fiber optic cables or single ormulti-fiber cables or connections. Further, as used herein, it isintended that terms “fiber optic cables” and/or “optical fibers” includeall types of single mode and multi-mode light waveguides, including oneor more bare optical fibers, loose-tube optical fibers, tight-bufferedoptical fibers, ribbonized optical fibers, bend-insensitive opticalfibers, or any other expedient of a medium for transmitting lightsignals. Many modifications and other embodiments set forth herein willcome to mind to one skilled in the art to which the embodiments pertainhaving the benefit of the teachings presented in the foregoingdescriptions and the associated drawings.

Therefore, it is to be understood that the description and claims arenot to be limited to the specific embodiments disclosed and thatmodifications and other embodiments are intended to be included withinthe scope of the appended claims. It is intended that the embodimentscover the modifications and variations of the embodiments provided theycome within the scope of the appended claims and their equivalents.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

What is claimed is:
 1. A wireless communication system, comprising: aplurality of remote units, each configured to provide RF communicationsto devices located in a coverage area; a downlink RF signal sourceinterface configured to receive downlink electrical radio frequency (RF)signals from at least one RF signal source; at least one opticalinterface module (OIM) configured to: receive and convert the downlinkelectrical RF signals from the downlink RF signal source interface intodownlink optical signals on at least one communication downlink; andreceive and convert uplink optical signals from at least one of theremote units into uplink electrical RF signals on at least onecommunication uplink; an uplink RF signal source interface configured toreceive and communicate the uplink electrical RF signals from the atleast one communication uplink to the at least one RF signal source; anda controller configured to: inject at least one calibration signal overthe at least one communication downlink; calibrate at least one downlinkgain in the at least one communication downlink based on a loss incurredin the at least one calibration signal in the at least one communicationdownlink; cause the at least one calibration signal to be switched fromthe at least one communication downlink to the at least onecommunication uplink; calibrate at least one uplink gain in the at leastone communication uplink, and calibrate at least one remote unitcalibration gain in the at least one remote unit by setting the at leastone remote unit calibration gain in at least one attenuator in the atleast one remote unit.
 2. The wireless communication system of claim 1,wherein the controller is further configured to calibrate a downlink RFsignal source calibration gain in the downlink RF signal sourceinterface by setting the downlink RF signal source calibration gain inat least one attenuator in the downlink RF signal source interface. 3.The wireless communication system of claim 2, wherein the controller isconfigured to calibrate the downlink RF signal source calibration gainand the at least one remote unit calibration gain while electrical RFsignals and optical signals are communicated over the at least onecommunication downlink.
 4. The wireless communication system of claim 1,wherein: a frequency of the at least one calibration signal is differentfrom a frequency of the downlink electrical RF signals; and the at leastone calibration signal is comprised of a plurality of calibrationsignals each having a different frequency.
 5. The wireless communicationsystem of claim 4, wherein the uplink gain is calibrated in the at leastone communication uplink based a loss incurred in the at least onecalibration signal in the at least one communication uplink.
 6. Thewireless communication system of claim 1, wherein the controller isfurther configured to: receive an input signal strength of the at leastone calibration signal on the at least one communication downlink; anddetermine a total downlink loss by comparing an end signal strength ofthe at least one calibration signal at the at least one remote unit withthe input signal strength of the at least one calibration signal.
 7. Thewireless communication system of claim 1, wherein the controller isfurther configured to: determine a total uplink loss for the at leastone communication uplink; determine an uplink RF signal source loss fromthe total uplink loss; and calibrate an uplink RF signal sourcecalibration gain in the uplink RF signal source interface based on theuplink RF signal source loss.
 8. The wireless communication system ofclaim 7, wherein the controller is further configured to: calibrate atleast one OIM calibration gain in the at least one OIM as the totaluplink loss minus the uplink RF signal source loss; and cause at leastone uplink calibration signal to be communicated over the at least onecommunication uplink.
 9. A wireless communication system, comprising: aplurality of remote units, each configured to provide RF communicationsto devices located in a coverage area; a downlink signal sourceinterface configured to receive downlink electrical signals from atleast one signal source; at least one optical interface module (OIM)configured to: receive and convert the downlink electrical signals fromthe downlink signal source interface into downlink optical signals on atleast one communication downlink; and receive and convert uplink opticalsignals from at least one of the remote units into uplink electricalsignals on at least one communication uplink; an uplink signal sourceinterface configured to receive and communicate the uplink electricalsignals from the at least one communication uplink to the at least onesignal source; and a controller configured to: inject at least onecalibration signal over the at least one communication downlink;calibrate at least one downlink gain in the at least one communicationdownlink based on a loss incurred in the at least one calibration signalin the at least one communication downlink; cause the at least onecalibration signal to be switched from the at least one communicationdownlink to the at least one communication uplink; calibrate at leastone uplink gain in the at least one communication uplink; determine atotal uplink loss for the at least one communication uplink; determinean uplink signal source loss from the total uplink loss; calibrate anuplink signal source calibration gain in the uplink signal sourceinterface based on the uplink signal source loss; and calibrate at leastone OIM calibration gain in the at least one OIM as the total uplinkloss minus the uplink signal source loss.
 10. The wireless communicationsystem of claim 9, wherein the controller is further configured to:calibrate at least one remote unit calibration gain in the at least oneremote unit; and calibrate the downlink signal source calibration gainand the at least one remote unit calibration gain while electricalsignals and optical signals are communicated over the at least onecommunication downlink.
 11. The wireless communication system of claim9, wherein the at least one OIM comprises a plurality of OIMs, whereinthe controller is configured to calibrate a separate OIM calibrationgain for each of the plurality of OIMs and cause at least one uplinkcalibration signal to be communicated over the at least onecommunication uplink.
 12. The wireless communication system of claim 9,wherein the controller is further configured to automatically calibratethe signal source calibration gain in the uplink signal source interfaceand the at least one OIM calibration gain in the at least one OIM.
 13. Awireless communication system, comprising: a plurality of remote units,each configured to provide RF communications to devices located in acoverage area; a downlink RF signal source interface configured toreceive downlink electrical radio frequency (RF) signals from at leastone RF signal source; at least one optical interface module (OIM)configured to: receive and convert the downlink electrical RF signalsfrom the downlink RF signal source interface into downlink opticalsignals on at least one communication downlink; and receive and convertuplink optical signals from at least one of the remote units into uplinkelectrical RF signals on at least one communication uplink; an uplink RFsignal source interface configured to receive and communicate the uplinkelectrical RF signals from the at least one communication uplink to theat least one RF signal source; and a controller configured to: inject atleast one calibration signal over the at least one communicationdownlink; calibrate at least one downlink gain in the at least onecommunication downlink; cause the at least one calibration signal to beswitched from the at least one communication downlink to the at leastone communication uplink; calibrate at least one uplink gain in the atleast one communication uplink based on a loss incurred in the at leastone calibration signal in the at least one communication uplink; andcalibrate at least one remote unit calibration gain in the at least oneremote unit by setting the at least one remote unit calibration gain inat least one attenuator in the at least one remote unit.
 14. Thewireless communication system of claim 13, wherein: a frequency of theat least one calibration signal is different from a frequency of thedownlink electrical RF signals; and the at least one calibration signalis comprised of a plurality of calibration signals each having adifferent frequency.
 15. The wireless communication system of claim 14,wherein the controller is further configured to calibrate a downlink RFsignal source calibration gain in the downlink RF signal sourceinterface by setting the downlink RF signal source calibration gain inat least one attenuator in the downlink RF signal source interface. 16.The wireless communication system of claim 15, wherein the controller isfurther configured to calibrate the downlink RF signal sourcecalibration gain and the at least one remote unit calibration gain whileelectrical RF signals and optical signals are communicated over the atleast one communication downlink.
 17. The wireless communication systemof claim 14, wherein the controller is further configured to: receive aninput signal strength of the at least one calibration signal on the atleast one communication downlink; and determine a total downlink loss bycomparing an end signal strength of the at least one calibration signalat the at least one remote unit with the input signal strength of the atleast one calibration signal.